Global weak solution for a equations in plasma
International Nuclear Information System (INIS)
Guo Boling; Huang Daiwen
2010-01-01
The existence of global weak solutions of the initial boundary value problem to a simplified equations, derived from the equations of two fluid system in plasma, is proven by using energy method and some embedding theorems in Sobolev-Orlicz space.
Large Time Behavior for Weak Solutions of the 3D Globally Modified Navier-Stokes Equations
Directory of Open Access Journals (Sweden)
Junbai Ren
2014-01-01
Full Text Available This paper is concerned with the large time behavior of the weak solutions for three-dimensional globally modified Navier-Stokes equations. With the aid of energy methods and auxiliary decay estimates together with Lp-Lq estimates of heat semigroup, we derive the optimal upper and lower decay estimates of the weak solutions for the globally modified Navier-Stokes equations as C1(1+t-3/4≤uL2≤C2(1+t-3/4, t>1. The decay rate is optimal since it coincides with that of heat equation.
Global, finite energy, weak solutions for the NLS with rough, time-dependent magnetic potentials
Antonelli, Paolo; Michelangeli, Alessandro; Scandone, Raffaele
2018-04-01
We prove the existence of weak solutions in the space of energy for a class of nonlinear Schrödinger equations in the presence of a external, rough, time-dependent magnetic potential. Under our assumptions, it is not possible to study the problem by means of usual arguments like resolvent techniques or Fourier integral operators, for example. We use a parabolic regularisation, and we solve the approximating Cauchy problem. This is achieved by obtaining suitable smoothing estimates for the dissipative evolution. The total mass and energy bounds allow to extend the solution globally in time. We then infer sufficient compactness properties in order to produce a global-in-time finite energy weak solution to our original problem.
Existence and non-uniqueness of global weak solutions to inviscid primitive and Boussinesq equations
Czech Academy of Sciences Publication Activity Database
Chiodaroli, E.; Michálek, Martin
2017-01-01
Roč. 353, č. 3 (2017), s. 1201-1216 ISSN 0010-3616 EU Projects: European Commission(XE) 320078 - MATHEF Institutional support: RVO:67985840 Keywords : Boussinesq equations * global weak solutions Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 2.500, year: 2016 https://link.springer.com/article/10.1007%2Fs00220-017-2846-5
Global weak solutions for a gas liquid model with external forces and general pressure law
Evje, Steinar; Friis, Helmer André
2011-01-01
This is a copy of an article previously published in; SIAM journal on applied mathematics, which has been made available here with permission. Original article; http://dx.doi.org/10.1137/100813336. In this work we show existence of global weak solutions for a two-phase gas-liquid model where the gas phase is represented by a general isothermal pressure law, whereas the liquid is assumed to be incompressible. To make the model relevant for pipe and well-flow applications we have included ex...
Global existence of weak solutions to dissipative transport equations with nonlocal velocity
Bae, Hantaek; Granero-Belinchón, Rafael; Lazar, Omar
2018-04-01
We consider 1D dissipative transport equations with nonlocal velocity field: where is a nonlocal operator given by a Fourier multiplier. We especially consider two types of nonlocal operators: (1) , the Hilbert transform, (2) . In this paper, we show several global existence of weak solutions depending on the range of γ, δ and α. When , we take initial data having finite energy, while we take initial data in weighted function spaces (in the real variables or in the Fourier variables), which have infinite energy, when .
Global weak solution to the 1D compressible Navier-Stokes equations with radiation
Czech Academy of Sciences Publication Activity Database
Ducomet, B.; Nečasová, Šárka
2010-01-01
Roč. 8, č. 3 (2010), s. 23-65 ISSN 1938-9787 R&D Projects: GA ČR GA201/08/0012 Institutional research plan: CEZ:AV0Z10190503 Keywords : weak solution * compressible flow * heat conductivity * radiation Subject RIV: BA - General Mathematics http://projecteuclid.org/euclid.cma/1279647305
Global existence of a weak solution for a model in radiation magnetohydrodynamics
Czech Academy of Sciences Publication Activity Database
Ducomet, B.; Kobera, M.; Nečasová, Šárka
2017-01-01
Roč. 150, č. 1 (2017), s. 43-65 ISSN 0167-8019 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : radiation magnetohydrodynamics * Navier-Stokes-Fourier system * weak solutio Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.702, year: 2016 https://link.springer.com/article/10.1007%2Fs10440-016-0093-y
Global existence of a weak solution for a model in radiation magnetohydrodynamics
Czech Academy of Sciences Publication Activity Database
Ducomet, B.; Kobera, M.; Nečasová, Šárka
2017-01-01
Roč. 150, č. 1 (2017), s. 43-65 ISSN 0167-8019 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : radiation magnetohydrodynamics * Navier-Stokes- Fourier system * weak solutio Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.702, year: 2016 https://link.springer.com/article/10.1007%2Fs10440-016-0093-y
Directory of Open Access Journals (Sweden)
Eliana Henriques de Brito
1990-01-01
Full Text Available In continuing from previous papers, where we studied the existence and uniqueness of the global solution and its asymptotic behavior as time t goes to infinity, we now search for a time-periodic weak solution u(t for the equation whose weak formulation in a Hilbert space H isddt(u′,v+δ(u′,v+αb(u,v+βa(u,v+(G(u,v=(h,vwhere: ′=d/dt; (′ is the inner product in H; b(u,v, a(u,v are given forms on subspaces U⊂W, respectively, of H; δ>0, α≥0, β≥0 are constants and α+β>0; G is the Gateaux derivative of a convex functional J:V⊂H→[0,∞ for V=U, when α>0 and V=W when α=0, hence β>0; v is a test function in V; h is a given function of t with values in H.
Global weak solutions for a compressible gas-liquid model with well-formation interaction
Evje, Steinar
The objective of this work is to explore a compressible gas-liquid model designed for modeling of well flow processes. We build into the model well-reservoir interaction by allowing flow of gas between well and formation (surrounding reservoir). Inflow of gas and subsequent expansion of gas as it ascends towards the top of the well (a so-called gas kick) represents a major concern for various well operations in the context of petroleum engineering. We obtain a global existence result under suitable assumptions on the regularity of initial data and the rate function that controls the flow of gas between well and formation. Uniqueness is also obtained by imposing more regularity on the initial data. The key estimates are to obtain appropriate lower and upper bounds on the gas and liquid masses. For that purpose we introduce a transformed version of the original model that is highly convenient for analysis of the original model. In particular, in the analysis of the transformed model additional terms, representing well-formation interaction, can be treated by natural extensions of arguments that previously have been employed for the single-phase Navier-Stokes model. The analysis ensures that transition to single-phase regions do not appear when the initial state is a true gas-liquid mixture.
Huang, Xiangdi; Li, Jing
2018-03-01
For the three-dimensional full compressible Navier-Stokes system describing the motion of a viscous, compressible, heat-conductive, and Newtonian polytropic fluid, we establish the global existence and uniqueness of classical solutions with smooth initial data which are of small energy but possibly large oscillations where the initial density is allowed to vanish. Moreover, for the initial data, which may be discontinuous and contain vacuum states, we also obtain the global existence of weak solutions. These results generalize previous ones on classical and weak solutions for initial density being strictly away from a vacuum, and are the first for global classical and weak solutions which may have large oscillations and can contain vacuum states.
Directory of Open Access Journals (Sweden)
Giai Giang Vo
2015-01-01
Full Text Available This paper is devoted to the study of a wave equation with a boundary condition of many-point type. The existence of weak solutions is proved by using the Galerkin method. Also, the uniqueness and the stability of solutions are established.
Directory of Open Access Journals (Sweden)
Oyelami, Benjamin Oyediran
2013-09-01
Full Text Available In this paper, criteria for the existence of weak solutions and uniformly weak bounded solution of impulsive heat equation containing maximum temperature are investigated and results obtained. An example is given for heat flow system with impulsive temperature using maximum temperature simulator and criteria for the uniformly weak bounded of solutions of the system are obtained.
From Suitable Weak Solutions to Entropy Viscosity
Guermond, Jean-Luc
2010-12-16
This paper focuses on the notion of suitable weak solutions for the three-dimensional incompressible Navier-Stokes equations and discusses the relevance of this notion to Computational Fluid Dynamics. The purpose of the paper is twofold (i) to recall basic mathematical properties of the three-dimensional incompressible Navier-Stokes equations and to show how they might relate to LES (ii) to introduce an entropy viscosity technique based on the notion of suitable weak solution and to illustrate numerically this concept. © 2010 Springer Science+Business Media, LLC.
Analytical solutions of weakly coupled map lattices using recurrence relations
Energy Technology Data Exchange (ETDEWEB)
Sotelo Herrera, Dolores, E-mail: dsh@dfmf.uned.e [Applied Maths, EUITI, UPM, Ronda de Valencia, 3-28012 Madrid (Spain); San Martin, Jesus [Applied Maths, EUITI, UPM, Ronda de Valencia, 3-28012 Madrid (Spain); Dep. Fisica Matematica y de Fluidos, UNED, Senda del Rey 9-28040 Madrid (Spain)
2009-07-20
By using asymptotic methods recurrence relations are found that rule weakly CML evolution, with both global and diffusive coupling. The solutions obtained from these relations are very general because they do not hold restrictions about boundary conditions, initial conditions and number of oscilators in the CML. Furthermore, oscillators are ruled by an arbitraty C{sup 2} function.
On weak solutions of stochastic differential equations
Czech Academy of Sciences Publication Activity Database
Hofmanová, Martina; Seidler, Jan
2012-01-01
Roč. 30, č. 1 (2012), s. 100-121 ISSN 0736-2994 R&D Projects: GA ČR GAP201/10/0752 Institutional research plan: CEZ:AV0Z10750506 Keywords : stochastic differential equations * weak solutions Subject RIV: BA - General Mathematics Impact factor: 0.303, year: 2012 http://library.utia.cas.cz/separaty/2012/SI/hofmanova-0373626.pdf
Do weak global stresses synchronize earthquakes?
Bendick, R.; Bilham, R.
2017-08-01
Insofar as slip in an earthquake is related to the strain accumulated near a fault since a previous earthquake, and this process repeats many times, the earthquake cycle approximates an autonomous oscillator. Its asymmetric slow accumulation of strain and rapid release is quite unlike the harmonic motion of a pendulum and need not be time predictable, but still resembles a class of repeating systems known as integrate-and-fire oscillators, whose behavior has been shown to demonstrate a remarkable ability to synchronize to either external or self-organized forcing. Given sufficient time and even very weak physical coupling, the phases of sets of such oscillators, with similar though not necessarily identical period, approach each other. Topological and time series analyses presented here demonstrate that earthquakes worldwide show evidence of such synchronization. Though numerous studies demonstrate that the composite temporal distribution of major earthquakes in the instrumental record is indistinguishable from random, the additional consideration of event renewal interval serves to identify earthquake groupings suggestive of synchronization that are absent in synthetic catalogs. We envisage the weak forces responsible for clustering originate from lithospheric strain induced by seismicity itself, by finite strains over teleseismic distances, or by other sources of lithospheric loading such as Earth's variable rotation. For example, quasi-periodic maxima in rotational deceleration are accompanied by increased global seismicity at multidecadal intervals.
Classical and Weak Solutions for Two Models in Mathematical Finance
Gyulov, Tihomir B.; Valkov, Radoslav L.
2011-12-01
We study two mathematical models, arising in financial mathematics. These models are one-dimensional analogues of the famous Black-Scholes equation on finite interval. The main difficulty is the degeneration at the both ends of the space interval. First, classical solutions are studied. Positivity and convexity properties of the solutions are discussed. Variational formulation in weighted Sobolev spaces is introduced and existence and uniqueness of the weak solution is proved. Maximum principle for weak solution is discussed.
Existence of Weak Solutions for a Nonlinear Elliptic System
Directory of Open Access Journals (Sweden)
Gilbert RobertP
2009-01-01
Full Text Available We investigate the existence of weak solutions to the following Dirichlet boundary value problem, which occurs when modeling an injection molding process with a partial slip condition on the boundary. We have in ; in ; , and on .
On weak solutions of stochastic differential equations II
Czech Academy of Sciences Publication Activity Database
Hofmanová, Martina; Seidler, Jan
2013-01-01
Roč. 31, č. 4 (2013), s. 663-670 ISSN 0736-2994 R&D Projects: GA ČR GAP201/10/0752 Institutional support: RVO:67985556 Keywords : fractional integrals * stochastic differential equations * weak solutions Subject RIV: BA - General Mathematics Impact factor: 0.664, year: 2013 http://library.utia.cas.cz/separaty/2013/SI/hofmanova-on weak solutions of stochastic differential equations II.pdf
Weak and strong solutions for differential equations in Banach spaces
International Nuclear Information System (INIS)
Gomaa, A.M.
2003-01-01
In this paper we give a generalization to recent results by using weak and strong measures of noncompactness. For f:[0,T]xE→E with E is a Banach space we prove that, under suitable assumptions, the Cauchy problem (fd((P) (ar((r((c(x(t)=f(t,x(t)),))(c(t/in R: =set membership[0,T],))))(r((c(x(0)=x 0 ,))(c()))))))) has at least one weak solution furthermore, with certain conditions, the Cauchy problem (P) has a solution. Next under a generalization of the compactness assumptions, we show that (P) has a solution too
Global Dislocations, Network Solutions
Pisani, Francis; Arquilla, John
2004-01-01
Globalization is essentially an attempt to foster universal commercial, social and political norms of behavior in a world where diversity—in all areas of interaction—has always ruled. Naturally, the great transformation called for by this vision of interconnectedness sparks tensions with existing institutions and practices. Yet there is nothing predetermined about the ways in which these tensions will be played out in the coming years; and by understanding the causes of potential difficulti...
On the existence of weak solutions of quantum stochastic differential ...
African Journals Online (AJOL)
We establish further results concerning the existence, uniqueness and stability of weak solutions of quantum stochastic differential equations (QSDEs). Our results are achieved by considering a more general Lipschit condition on the coefficients than our previous considerations in [1]. We exhibit a class of Lipschitzian ...
What is behind the weakness in global investment?
Leboeuf, Maxime; Fay, Bob
2016-01-01
The recovery in private business investment globally remains extremely weak more than seven years after the financial crisis. This paper contributes to the ongoing policy debate on the factors behind this weakness by analyzing the role of growth prospects and uncertainty in explaining developments in non-residential private business investment in large advanced economies since the crisis. Augmenting the traditional models of investment with measures of growth expectations for output and uncer...
Weak ionization of the global ionosphere in solar cycle 24
Directory of Open Access Journals (Sweden)
Y. Q. Hao
2014-07-01
Full Text Available Following prolonged and extremely quiet solar activity from 2008 to 2009, the 24th solar cycle started slowly. It has been almost 5 years since then. The measurement of ionospheric critical frequency (foF2 shows the fact that solar activity has been significantly lower in the first half of cycle 24, compared to the average levels of cycles 19 to 23; the data of global average total electron content (TEC confirm that the global ionosphere around the cycle 24 peak is much more weakly ionized, in contrast to cycle 23. The weak ionization has been more notable since the year 2012, when both the ionosphere and solar activity were expected to be approaching their maximum level. The undersupply of solar extreme ultraviolet (EUV irradiance somewhat continues after the 2008–2009 minimum, and is considered to be the main cause of the weak ionization. It further implies that the thermosphere and ionosphere in the first solar cycle of this millennium would probably differ from what we have learned from the previous cycles of the space age.
A Weak Solution of a Stochastic Nonlinear Problem
Directory of Open Access Journals (Sweden)
M. L. Hadji
2015-01-01
Full Text Available We consider a problem modeling a porous medium with a random perturbation. This model occurs in many applications such as biology, medical sciences, oil exploitation, and chemical engineering. Many authors focused their study mostly on the deterministic case. The more classical one was due to Biot in the 50s, where he suggested to ignore everything that happens at the microscopic level, to apply the principles of the continuum mechanics at the macroscopic level. Here we consider a stochastic problem, that is, a problem with a random perturbation. First we prove a result on the existence and uniqueness of the solution, by making use of the weak formulation. Furthermore, we use a numerical scheme based on finite differences to present numerical results.
Global Solution of Atmospheric Circulation Models with Humidity Effect
Luo, Hong
2014-01-01
The atmospheric circulation models are deduced from the very complex atmospheric circulation models based on the actual background and meteorological data. The models are able to show features of atmospheric circulation and are easy to be studied. It is proved that existence of global solutions to atmospheric circulation models with the use of the $T$-weakly continuous operator.
Global Solutions to the Coupled Chemotaxis-Fluid Equations
Duan, Renjun
2010-08-10
In this paper, we are concerned with a model arising from biology, which is a coupled system of the chemotaxis equations and the viscous incompressible fluid equations through transport and external forcing. The global existence of solutions to the Cauchy problem is investigated under certain conditions. Precisely, for the Chemotaxis-Navier-Stokes system over three space dimensions, we obtain global existence and rates of convergence on classical solutions near constant states. When the fluid motion is described by the simpler Stokes equations, we prove global existence of weak solutions in two space dimensions for cell density with finite mass, first-order spatial moment and entropy provided that the external forcing is weak or the substrate concentration is small. © Taylor & Francis Group, LLC.
Existence of positive weak solutions for a class of singular elliptic equations
Directory of Open Access Journals (Sweden)
Li Xia
2011-08-01
Full Text Available In this note, we are concerned with positive solutions for a class of singular elliptic equations. Under some conditions, we obtain weak solutions for the equations by elliptic regularization method and sub-super solution method.
Czech Academy of Sciences Publication Activity Database
Feireisl, Eduard; Jin, B.J.; Novotný, A.
2012-01-01
Roč. 14, č. 4 (2012), s. 717-730 ISSN 1422-6928 R&D Projects: GA ČR GA201/09/0917 Institutional research plan: CEZ:AV0Z10190503 Keywords : suitable weak solution * weak-strong uniqueness * compressible Navier-Stokes system Subject RIV: BA - General Mathematics Impact factor: 1.415, year: 2012 http://link.springer.com/article/10.1007%2Fs00021-011-0091-9
of Weak Solutions of an Abstract Evolution Equation with a Scalar Type Spectral Operator
Directory of Open Access Journals (Sweden)
Marat V. Markin
2011-01-01
Full Text Available For the evolution equation (=( with a scalar type spectral operator in a Banach space, conditions on are found that are necessary and sufficient for all weak solutions of the equation on [0,∞ to be strongly infinite differentiable on [0,∞ or [0,∞. Certain effects of smoothness improvement of the weak solutions are analyzed.
Weak stability of Lagrangian solutions to the semigeostrophic equations
International Nuclear Information System (INIS)
Faria, Josiane C O; Lopes Filho, Milton C; Nussenzveig Lopes, Helena J
2009-01-01
In (Cullen and Feldman 2006 SIAM J. Math. Anal. 37 137–95), Cullen and Feldman proved the existence of Lagrangian solutions for the semigeostrophic system in physical variables with initial potential vorticity in L p , p > 1. Here, we show that a subsequence of the Lagrangian solutions corresponding to a strongly convergent sequence of initial potential vorticities in L 1 converges strongly in L q , q < ∞, to a Lagrangian solution, in particular extending the existence result of Cullen and Feldman to the case p = 1. We also present a counterexample for Lagrangian solutions corresponding to a sequence of initial potential vorticities converging in BM. The analytical tools used include techniques from optimal transportation, Ambrosio's results on transport by BV vector fields and Orlicz spaces
Automatic protein structure solution from weak X-ray data
Skubák, Pavol; Pannu, Navraj S.
2013-11-01
Determining new protein structures from X-ray diffraction data at low resolution or with a weak anomalous signal is a difficult and often an impossible task. Here we propose a multivariate algorithm that simultaneously combines the structure determination steps. In tests on over 140 real data sets from the protein data bank, we show that this combined approach can automatically build models where current algorithms fail, including an anisotropically diffracting 3.88 Å RNA polymerase II data set. The method seamlessly automates the process, is ideal for non-specialists and provides a mathematical framework for successfully combining various sources of information in image processing.
Haffeld, Just Balstad; Siem, Harald; Røttingen, John-Arne
2010-01-01
The article comprises a conceptual framework to analyze the strengths and weaknesses of a global health convention. The analyses are inspired by Lawrence Gostin's suggested Framework Convention on Global Health. The analytical model takes a starting-point in events tentatively following a logic sequence: Input (global health funding), Processes (coordination, cooperation, accountability, allocation of aid), Output (definition of basic survival needs), Outcome (access to health services), and Impact (health for all). It then examines to what degree binding international regulations can create order in such a sequence of events. We conclude that a global health convention could be an appropriate instrument to deal with some of the problems of global health. We also show that some of the tasks preceding a convention approach might be to muster international support for supra-national health regulations, negotiate compromises between existing stakeholders in the global health arena, and to utilize WHO as a platform for further discussions on a global health convention. © 2010 American Society of Law, Medicine & Ethics, Inc.
Quasi-linear PDEs and forward-backward stochastic differential equations: Weak solutions
Feng, Chunrong; Wang, Xince; Zhao, Huaizhong
2018-01-01
In this paper, we study the existence, uniqueness and the probabilistic representation of the weak solutions of quasi-linear parabolic and elliptic partial differential equations (PDEs) in the Sobolev space Hρ1 (Rd). For this, we study first the solutions of forward-backward stochastic differential equations (FBSDEs) with smooth coefficients, regularity of solutions and their connection with classical solutions of quasi-linear parabolic PDEs. Then using the approximation procedure, we establish their convergence in the Sobolev space to the solutions of the FBSDES in the space Lρ2 (Rd ;Rd) ⊗ Lρ2 (Rd ;Rk) ⊗ Lρ2 (Rd ;R k × d). This gives a connection with the weak solutions of quasi-linear parabolic PDEs. Finally, we study the unique weak solutions of quasi-linear elliptic PDEs using the solutions of the FBSDEs on infinite horizon.
Weak solutions for Euler systems with non-local interactions
Czech Academy of Sciences Publication Activity Database
Carrillo, J. A.; Feireisl, Eduard; Gwiazda, P.; Swierczewska-Gwiazda, A.
2017-01-01
Roč. 95, č. 3 (2017), s. 705-724 ISSN 0024-6107 EU Projects: European Commission(XE) 320078 - MATHEF Institutional support: RVO:67985840 Keywords : Euler system * dissipative solutions * Newtonian interaction Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.895, year: 2016 http://onlinelibrary. wiley .com/doi/10.1112/jlms.12027/abstract
Weak solutions for Euler systems with non-local interactions
Czech Academy of Sciences Publication Activity Database
Carrillo, J. A.; Feireisl, Eduard; Gwiazda, P.; Swierczewska-Gwiazda, A.
2017-01-01
Roč. 95, č. 3 (2017), s. 705-724 ISSN 0024-6107 EU Projects: European Commission(XE) 320078 - MATHEF Institutional support: RVO:67985840 Keywords : Euler system * dissipative solutions * Newtonian interaction Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.895, year: 2016 http://onlinelibrary.wiley.com/doi/10.1112/jlms.12027/abstract
Global existence of solutions for some coupled systems of reaction-diffusion equations
Salem, Abdelmalek; Amar, Youkana
2010-01-01
The aim of this work is to study the global existence of solutions for some coupled systems of reaction diffusion which describe the spread within a population of infectious disease. We consider a triangular matrix diffusion and we show that we can prove global existence of classical solutions for the nonlinearities of weakly exponential growth.
Existence of weak solutions to first-order stationary mean-field games with Dirichlet conditions
Ferreira, Rita
2018-04-19
In this paper, we study first-order stationary monotone mean-field games (MFGs) with Dirichlet boundary conditions. While for Hamilton--Jacobi equations Dirichlet conditions may not be satisfied, here, we establish the existence of solutions of MFGs that satisfy those conditions. To construct these solutions, we introduce a monotone regularized problem. Applying Schaefer\\'s fixed-point theorem and using the monotonicity of the MFG, we verify that there exists a unique weak solution to the regularized problem. Finally, we take the limit of the solutions of the regularized problem and using Minty\\'s method, we show the existence of weak solutions to the original MFG.
Weak Frictional Healing as Controlled by Intergranular Pressure Solution
He, C.
2017-12-01
Unstable fault slips due to velocity weakening requires a frictional healing effect that is stronger than the instantaneous rate effect. Based on a previous analytical result regarding the healing effect at spherical contacts by intergranular pressure solution (He et al., 2013), we extend the analysis to incorporate the full range of dilatancy angles from π/6 to -π/6, covering uphill and downhill situations of many contacts with different dilatancy angles. Assuming that both healing effect (parameter b) and instantaneous rate effect (parameter a) are controlled by intergranular pressure solution, and averaging over the whole range of dilatancy angle, our analysis derives each of the two effects as a function of temperature. The result shows velocity weakening for friction coefficient>0.274. As hydrothermal conditions are important for deep portion of actual fault zones, the strength of velocity weakening is of interest when the related faulting behavior is concerned. As a measure of the strength of velocity weakening, the derived ratio b/a fully controlled by pressure solution shows an upper bound of 1.22. Data analyses in previous studies on plagioclase (He et al., 2013) and oceanic basalt (Zhang and He, 2017) shows a range of b/a =1.05-1.2, consistent with the analytical result. The valuescontacts, especially under hydrothermal conditions in fault zones. For comparable ratios of system stiffness to the critical value, numerical simulations with a single-degree-of-freedom system show that a smaller b/a significantly reduces the peak slip velocity as a result of reduced period of free oscillation corresponding to the lower stiffness (Fig.1). This is an effect similar to that by reduced effective normal stress due to overpressure of pore fluid, which lowers the stiffness suitable for unstable slips, thus weakens the peak slip velocity.
Weak solutions to stochastic differential equations driven by fractional Brownian motion
Czech Academy of Sciences Publication Activity Database
Šnupárková, Jana
2009-01-01
Roč. 59, č. 4 (2009), s. 879-907 ISSN 0011-4642 R&D Projects: GA ČR GA201/07/0237 Institutional research plan: CEZ:AV0Z10750506 Keywords : fractional Brownian motion * weak solutions Subject RIV: BA - General Mathematics Impact factor: 0.306, year: 2009 http://library.utia.cas.cz/separaty/2009/SI/snuparkova-weak solutions to stochastic differential equations driven by fractional brownian motion.pdf
Mucha, Piotr B.; Peszek, Jan
2018-01-01
The Cucker-Smale flocking model belongs to a wide class of kinetic models that describe a collective motion of interacting particles that exhibit some specific tendency, e.g. to aggregate, flock or disperse. This paper examines the kinetic Cucker-Smale equation with a singular communication weight. Given a compactly supported measure as an initial datum we construct a global in time weak measure-valued solution in the space {C_{weak}(0,∞M)}. The solution is defined as a mean-field limit of the empirical distributions of particles, the dynamics of which is governed by the Cucker-Smale particle system. The studied communication weight is {ψ(s)=|s|^{-α}} with {α \\in (0,1/2)}. This range of singularity admits the sticking of characteristics/trajectories. The second result concerns the weak-atomic uniqueness property stating that a weak solution initiated by a finite sum of atoms, i.e. Dirac deltas in the form {m_i δ_{x_i} ⊗ δ_{v_i}}, preserves its atomic structure. Hence these coincide with unique solutions to the system of ODEs associated with the Cucker-Smale particle system.
Admissibility of weak solutions for the compressible Euler equations, n ≥ 2.
Slemrod, Marshall
2013-12-28
This paper compares three popular notions of admissibility for weak solutions of the compressible isentropic Euler equations of gas dynamics: (i) the viscosity criterion, (ii) the entropy inequality (the thermodynamically admissible isentropic solutions), and (iii) the viscosity-capillarity criterion. An exact summation of the Chapman-Enskog expansion for Grad's moment system suggests that it is the third criterion that is representing the kinetic theory of gases. This, in turn, may shed some light on the ability to recover weak solutions of the Euler equations via a hydrodynamic limit.
Partial regularity of weak solutions to a PDE system with cubic nonlinearity
Liu, Jian-Guo; Xu, Xiangsheng
2018-04-01
In this paper we investigate regularity properties of weak solutions to a PDE system that arises in the study of biological transport networks. The system consists of a possibly singular elliptic equation for the scalar pressure of the underlying biological network coupled to a diffusion equation for the conductance vector of the network. There are several different types of nonlinearities in the system. Of particular mathematical interest is a term that is a polynomial function of solutions and their partial derivatives and this polynomial function has degree three. That is, the system contains a cubic nonlinearity. Only weak solutions to the system have been shown to exist. The regularity theory for the system remains fundamentally incomplete. In particular, it is not known whether or not weak solutions develop singularities. In this paper we obtain a partial regularity theorem, which gives an estimate for the parabolic Hausdorff dimension of the set of possible singular points.
Global solutions of 1 + 1 gravity
International Nuclear Information System (INIS)
Kloesch, T.
1997-03-01
A classification of all global solutions for generalized 2D dilaton gravity models (with Lorentzian signature) including generalizations with non-trivial torsion is presented. After reviewing several coordinate systems (and - as a by-product - finding global coordinates for the Reissner-Nordstroem solution), the equations of motion are solved locally. The maximally extended universal covering solutions are then constructed by applying a simple gluing procedure to the Eddington-Finkelstein coordinate patches. This is demonstrated at a few examples, and some subtleties concerning the concept of Penrose diagrams are pointed out. The multiply connected solutions are obtained from the simply connected ones by factorization by discrete symmetry subgroups. It will be found that for generic models maximally extended solutions on noncompact surfaces of arbitrary genus with an arbitrary non-zero number of holes can be obtained. Furthermore, we determine all discrete and continuous parameters labeling these factor solutions and specify their geometrical interpretation. Remarks on a few cases not covered by the above approach and some pathological examples conclude the work. (author)
The global health concept of the German government: strengths, weaknesses, and opportunities
Bozorgmehr, Kayvan; Bruchhausen, Walter; Hein, Wolfgang; Knipper, Michael; Korte, Rolf; Razum, Oliver; Tinnemann, Peter
2014-01-01
Recognising global health as a rapidly emerging policy field, the German federal government recently released a national concept note for global health politics (July 10, 2013). As the German government could have a significant impact on health globally by making a coherent, evidence-informed, and long-term commitment in this field, we offer an initial appraisal of the strengths, weaknesses, and opportunities for development recognised in this document. We conclude that the national concept i...
Weak asymptotic solution for a non-strictly hyperbolic system of conservation laws-II
Directory of Open Access Journals (Sweden)
Manas Ranjan Sahoo
2016-04-01
Full Text Available In this article we introduce a concept of entropy weak asymptotic solution for a system of conservation laws and construct the same for a prolonged system of conservation laws which is highly non-strictly hyperbolic. This is first done for Riemann type initial data by introducing $\\delta,\\delta',\\delta''$ waves along a discontinuity curve and then for general initial data by piecing together the Riemann solutions.
On the weak solutions to the equations of a compressible heat conducting gas
Czech Academy of Sciences Publication Activity Database
Chiodaroli, E.; Feireisl, Eduard; Kreml, O.
2015-01-01
Roč. 32, č. 1 (2015), s. 225-243 ISSN 0294-1449 EU Projects: European Commission(XE) 320078 - MATHEF Institutional support: RVO:67985840 Keywords : Euler -Fourier system * convex integration * weak solution Subject RIV: BA - General Mathematics Impact factor: 2.066, year: 2015 http://www.sciencedirect.com/science/article/pii/S0294144913001339
Czech Academy of Sciences Publication Activity Database
Feireisl, Eduard; Lu, Y.; Süli, E.
2016-01-01
Roč. 443, č. 1 (2016), s. 322-351 ISSN 0022-247X Keywords : weak solutions * kinetic polymer models * FENE chain Subject RIV: BA - General Mathematics Impact factor: 1.064, year: 2016 http://www.sciencedirect.com/science/article/pii/S0022247X1630172X
Existence of weak solutions in lower order Sobolev space for a Camassa-Holm-type equation
International Nuclear Information System (INIS)
Lai Shaoyong; Wu Yonghong
2010-01-01
A generalized Camassa-Holm equation containing a nonlinear dissipative effect is investigated. The existence of the weak solution of the equation in lower order Sobolev space H s with 1
Remark on regularity criteria of a weak solution to the 3D MHD equations
Directory of Open Access Journals (Sweden)
Jae-Myoung Kim
2017-04-01
Full Text Available We study the regularity conditions for a weak solution to 3D MHD equations in a whole space $\\mathbb{R}^3$, based on the papers [C. He, Y. Wang, J. Differential Equations, 238(2007, No. 1, 1–17] and [W. Wang, J. Math. Anal. Appl., 328(2007, No. 2, 1082–1086].
On the weak solutions to the equations of a compressible heat conducting gas
Czech Academy of Sciences Publication Activity Database
Chiodaroli, E.; Feireisl, Eduard; Kreml, O.
2015-01-01
Roč. 32, č. 1 (2015), s. 225-243 ISSN 0294-1449 EU Projects: European Commission(XE) 320078 - MATHEF Institutional support: RVO:67985840 Keywords : Euler-Fourier system * convex integration * weak solution Subject RIV: BA - General Mathematics Impact factor: 2.066, year: 2015 http://www.sciencedirect.com/science/article/pii/S0294144913001339
Towards combined global monthly gravity field solutions
Jaeggi, Adrian; Meyer, Ulrich; Beutler, Gerhard; Weigelt, Matthias; van Dam, Tonie; Mayer-Gürr, Torsten; Flury, Jakob; Flechtner, Frank; Dahle, Christoph; Lemoine, Jean-Michel; Bruinsma, Sean
2014-05-01
Currently, official GRACE Science Data System (SDS) monthly gravity field solutions are generated independently by the Centre for Space Research (CSR) and the German Research Centre for Geosciences (GFZ). Additional GRACE SDS monthly fields are provided by the Jet Propulsion Laboratory (JPL) for validation and outside the SDS by a number of other institutions worldwide. Although the adopted background models and processing standards have been harmonized more and more by the various processing centers during the past years, notable differences still exist and the users are more or less left alone with a decision which model to choose for their individual applications. This procedure seriously limits the accessibility of these valuable data. Combinations are well established in the area of other space geodetic techniques, such as the Global Navigation Satellite Systems (GNSS), Satellite Laser Ranging (SLR), and Very Long Baseline Interferometry (VLBI). Regularly comparing and combining space-geodetic products has tremendously increased the usefulness of the products in a wide range of disciplines and scientific applications. Therefore, we propose in a first step to mutually compare the large variety of available monthly GRACE gravity field solutions, e.g., by assessing the signal content over selected regions, by estimating the noise over the oceans, and by performing significance tests. We make the attempt to assign different solution characteristics to different processing strategies in order to identify subsets of solutions, which are based on similar processing strategies. Using these subsets we will in a second step explore ways to generate combined solutions, e.g., based on a weighted average of the individual solutions using empirical weights derived from pair-wise comparisons. We will also assess the quality of such a combined solution and discuss the potential benefits for the GRACE and GRACE-FO user community, but also address minimum processing
Small data global solutions for the Camassa–Choi equations
Harrop-Griffiths, Benjamin; Marzuola, Jeremy L.
2018-05-01
We consider solutions to the Cauchy problem for an internal-wave model derived by Camassa–Choi (1996 J. Fluid Mech. 313 83–103). This model is a natural generalization of the Benjamin–Ono and intermediate long wave equations for weak transverse effects as in the case of the Kadomtsev–Petviashvili equations for the Korteweg-de Vries equation. For that reason they are often referred to as the KP-ILW or the KP–Benjamin–Ono equations regarding finite or infinite depth respectively. We prove the existence and long-time dynamics of global solutions from small, smooth, spatially localized initial data on . The techniques applied here involve testing by wave packet techniques developed by Ifrim and Tataru in (2015 Nonlinearity 28 2661–75 2016 Bull. Soc. Math. France 144 369–94).
A Note on Weak Solutions of Conservation Laws and Energy/Entropy Conservation
Gwiazda, Piotr; Michálek, Martin; Świerczewska-Gwiazda, Agnieszka
2018-03-01
A common feature of systems of conservation laws of continuum physics is that they are endowed with natural companion laws which are in such cases most often related to the second law of thermodynamics. This observation easily generalizes to any symmetrizable system of conservation laws; they are endowed with nontrivial companion conservation laws, which are immediately satisfied by classical solutions. Not surprisingly, weak solutions may fail to satisfy companion laws, which are then often relaxed from equality to inequality and overtake the role of physical admissibility conditions for weak solutions. We want to answer the question: what is a critical regularity of weak solutions to a general system of conservation laws to satisfy an associated companion law as an equality? An archetypal example of such a result was derived for the incompressible Euler system in the context of Onsager's conjecture in the early nineties. This general result can serve as a simple criterion to numerous systems of mathematical physics to prescribe the regularity of solutions needed for an appropriate companion law to be satisfied.
A GENERAL-SOLUTION FOR A CLASS OF WEAKLY CONSTRAINED LINEAR-REGRESSION PROBLEMS
TENBERGE, JMF
1991-01-01
This paper contains a globally optimal solution for a class of functions composed of a linear regression function and a penalty function for the sum of squared regression weights. Global optimality is obtained from inequalities rather than from partial derivatives of a Lagrangian function.
Weakly Hydrated Surfaces and the Binding Interactions of Small Biological Solutes
Energy Technology Data Exchange (ETDEWEB)
Brady, J. W.; Tavagnacco, L.; Ehrlich, L.; Chen, M.; Schnupf, U.; Himmel, M. E.; Saboungi, M. L.; Cesaro, A.
2012-04-01
Extended planar hydrophobic surfaces, such as are found in the side chains of the amino acids histidine, phenylalanine, tyrosine, and tryptophan, exhibit an affinity for the weakly hydrated faces of glucopyranose. In addition, molecular species such as these, including indole, caffeine, and imidazole, exhibit a weak tendency to pair together by hydrophobic stacking in aqueous solution. These interactions can be partially understood in terms of recent models for the hydration of extended hydrophobic faces and should provide insight into the architecture of sugar-binding sites in proteins.
Stormy Weather: 101 Solutions to Global Climate Change.
Dauncey, Guy
This document presents 101 solutions to global climate change. These solutions are actions that are well suited to every level of society. This book creates awareness about global climate change. The history of Earth and the greenhouse effect are discussed, and explanations and solutions to global climate change are provided including traveling…
Punshon-Smith, Samuel; Smith, Scott
2018-02-01
This article studies the Cauchy problem for the Boltzmann equation with stochastic kinetic transport. Under a cut-off assumption on the collision kernel and a coloring hypothesis for the noise coefficients, we prove the global existence of renormalized (in the sense of DiPerna/Lions) martingale solutions to the Boltzmann equation for large initial data with finite mass, energy, and entropy. Our analysis includes a detailed study of weak martingale solutions to a class of linear stochastic kinetic equations. This study includes a criterion for renormalization, the weak closedness of the solution set, and tightness of velocity averages in {{L}1}.
Existence of positive weak solutions for (p,q)-Laplacian nonlinear ...
Indian Academy of Sciences (India)
where pu = div(|∇u|p−2 ∇u),p,q > 1 and λ, μ are positive parameters, and. ⊂ RN is a bounded domain with smooth boundary ∂ and g, c are nonnega- tive and continuous functions and f, h, a, b are C1 nondecreasing functions satisfying a(0), b(0) ≥ 0. We have proved the existence of a positive weak solution for λ, μ large.
The Navier-Stokes-Fourier system: From weak solutions to numerical analysis
Czech Academy of Sciences Publication Activity Database
Feireisl, Eduard
2015-01-01
Roč. 35, č. 3 (2015), s. 185-193 ISSN 0174-4747 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : Navier-Stokes-Fourier system * weak solution * mixed finite-volume finite-element numerical scheme Subject RIV: BA - General Mathematics http://www.degruyter.com/view/j/anly.2015.35.issue-3/anly-2014-1300/anly-2014-1300. xml
Czech Academy of Sciences Publication Activity Database
Chiodaroli, E.; Kreml, Ondřej
2018-01-01
Roč. 31, č. 4 (2018), s. 1441-1460 ISSN 0951-7715 R&D Projects: GA ČR(CZ) GJ17-01694Y Institutional support: RVO:67985840 Keywords : Riemann problem * non-uniqueness * weak solutions Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.767, year: 2016 http://iopscience.iop.org/ article /10.1088/1361-6544/aaa10d/meta
The Navier-Stokes-Fourier system: From weak solutions to numerical analysis
Czech Academy of Sciences Publication Activity Database
Feireisl, Eduard
2015-01-01
Roč. 35, č. 3 (2015), s. 185-193 ISSN 0174-4747 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : Navier-Stokes- Fourier system * weak solution * mixed finite-volume finite-element numerical scheme Subject RIV: BA - General Mathematics http://www.degruyter.com/view/j/anly.2015.35.issue-3/anly-2014-1300/anly-2014-1300.xml
On weak solutions to a diffuse interface model of a binary mixture of compressible fluids
Czech Academy of Sciences Publication Activity Database
Feireisl, Eduard
2016-01-01
Roč. 9, č. 1 (2016), s. 173-183 ISSN 1937-1632 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : Euler-Cahn-Hilliard system * weak solution * diffuse interface model Subject RIV: BA - General Mathematics Impact factor: 0.781, year: 2016 http://aimsciences.org/ journals /displayArticlesnew.jsp?paperID=12093
On weak solutions to a diffuse interface model of a binary mixture of compressible fluids
Czech Academy of Sciences Publication Activity Database
Feireisl, Eduard
2016-01-01
Roč. 9, č. 1 (2016), s. 173-183 ISSN 1937-1632 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : Euler-Cahn-Hilliard system * weak solution * diffuse interface model Subject RIV: BA - General Mathematics Impact factor: 0.781, year: 2016 http://aimsciences.org/journals/displayArticlesnew.jsp?paperID=12093
Non-uniqueness of admissible weak solutions to the Riemann problem for isentropic Euler equations
Chiodaroli, Elisabetta; Kreml, Ondřej
2018-04-01
We study the Riemann problem for multidimensional compressible isentropic Euler equations. Using the framework developed in Chiodaroli et al (2015 Commun. Pure Appl. Math. 68 1157–90), and based on the techniques of De Lellis and Székelyhidi (2010 Arch. Ration. Mech. Anal. 195 225–60), we extend the results of Chiodaroli and Kreml (2014 Arch. Ration. Mech. Anal. 214 1019–49) and prove that it is possible to characterize a set of Riemann data, giving rise to a self-similar solution consisting of one admissible shock and one rarefaction wave, for which the problem also admits infinitely many admissible weak solutions.
On uniqueness of weak solutions for the thin-film equation
John, Dominik
2015-10-01
In any number of space variables, we study the Cauchy problem related to the fourth-order degenerate diffusion equation ∂s h + ∇ ṡ (h∇Δh) = 0. This equation, derived from a lubrication approximation, also models the surface tension dominated flow of a thin viscous film in the Hele-Shaw cell. Our focus is on uniqueness of weak solutions in the "complete wetting" regime, when a zero contact angle between liquid and solid is imposed. In this case, we transform the problem by zooming into the free boundary and look at small Lipschitz perturbations of a quadratic stationary solution. In the perturbational setting, the main difficulty is to construct scale invariant function spaces in such a way that they are compatible with the structure of the nonlinear equation. Here we rely on the theory of singular integrals in spaces of homogeneous type to obtain linear estimates in these functions spaces which provide "optimal" conditions on the initial data under which a unique solution exists. In fact, this solution can be used to define a class of functions in which the original initial value problem has a unique (weak) solution. Moreover, we show that the interface between empty and wetted regions is an analytic hypersurface in time and space.
On Global Solutions for the Cauchy Problem of a Boussinesq-Type Equation
Taskesen, Hatice; Polat, Necat; Ertaş, Abdulkadir
2012-01-01
We will give conditions which will guarantee the existence of global weak solutions of the Boussinesq-type equation with power-type nonlinearity $\\gamma {|u|}^{p}$ and supercritical initial energy. By defining new functionals and using potential well method, we readdressed the initial value problem of the Boussinesq-type equation for the supercritical initial energy case.
Directory of Open Access Journals (Sweden)
Jian Liu
2013-09-01
Full Text Available In this article, we consider the free boundary value problem for one-dimensional compressible bipolar Navier-Stokes-Possion (BNSP equations with density-dependent viscosities. For general initial data with finite energy and the density connecting with vacuum continuously, we prove the global existence of the weak solution. This extends the previous results for compressible NS [27] to NSP.
Energy Technology Data Exchange (ETDEWEB)
Nomura, Yasushi; Takada, Tomoyuki; Kuroishi, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kadotani, Hiroyuki [Shizuoka Sangyo Univ., Iwata, Shizuoka (Japan)
2003-03-01
In the case of Monte Carlo calculation to obtain a neutron multiplication factor for a system of weak neutron interaction, there might be some problems concerning convergence of the solution. Concerning this difficulty in the computer code calculations, theoretical derivation was made from the general neutron transport equation and consideration was given for acceleration of solution convergence by using the matrix eigenvector in this report. Accordingly, matrix eigenvector calculation scheme was incorporated together with procedure to make acceleration of convergence into the continuous energy Monte Carlo code MCNP. Furthermore, effectiveness of acceleration of solution convergence by matrix eigenvector was ascertained with the results obtained by applying to the two OECD/NEA criticality analysis benchmark problems. (author)
Tompkins, D. R., Jr.
1974-01-01
For both the linearized prolate and oblate problems, perturbation series for all orders of eccentricity are obtained. The 'weak separation' method of solving partial-differential-equation boundary-value problems assumes that each linearly independent solution is a sum of products of single-variable functions. The method is applied to a hierarchy of partial differential equations. The weak-separation solutions are constructed by generalizing only the Bessel functions of the homogeneous solution.
Global public goods for health: weaknesses and opportunities in the global health system.
Moon, Suerie; Røttingen, John-Arne; Frenk, Julio
2017-04-01
Since at least the 1990s, there has been growing recognition that societies need global public goods (GPGs) in order to protect and promote public health. While the term GPG is sometimes used loosely to denote that which is 'good' for the global public, we restrict our use of the term to its technical definition (goods that are non-excludable and non-rival in consumption) for its useful analytical clarity. Examples of important GPGs for health include standards and guidelines, research on the causes and treatment of disease, and comparative evidence and analysis. While institutions for providing public goods are relatively well developed at the national level - being clearly recognized as a responsibility of sovereign states - institutional arrangements to do so remain fragmented and thin at the global level. For example, the World Health Organization, mandated to provide many GPGs, is not appropriately financed to do so. Three steps are needed to better govern the financing and provision of GPGs for health: first, improved data to develop a clearer picture of how much money is currently going to providing which types of GPGs; second, a legitimate global political process to decide upon priority missing GPGs, followed by estimates of total amounts needed; and third, financing streams for GPGs from governments and private sources, to be channeled through new or existing institutions. Financing should go toward fully financing some GPGs, complementing or supplementing existing national or international financing for others, or deploying funds to make potential GPGs less 'excludable' by putting them into the public domain. As globalization deepens the degree of interdependence between countries and as formerly low-income economies advance, there may be less relative need for development assistance to meet basic health care needs, and greater relative need to finance GPGs. Strengthening global arrangements for GPGs today is a worthy investment for improved global
On existence of weak solutions to a Cauchy problem for one class of conservation laws
Directory of Open Access Journals (Sweden)
P. I. Kogut
2015-02-01
Full Text Available We discuss the existence of weak solutions to the Cauchy problem for one classof hyperbolic conservation laws that models a highly re-entrant production system.The output of the factory is described as a function of the work in progress and theposition of the so-called push-pull point (PPP where we separate the beginning ofthe factory employing a push policy from the end of the factory, which uses a pullpolicy. The main question we discuss in this paper is about the optimal choice ofthe input in-ux, push and pull constituents, and the position of PPP.
On the Construction and Properties of Weak Solutions Describing Dynamic Cavitation
Miroshnikov, Alexey
2014-08-21
We consider the problem of dynamic cavity formation in isotropic compressible nonlinear elastic media. For the equations of radial elasticity we construct self-similar weak solutions that describe a cavity emanating from a state of uniform deformation. For dimensions d=2,3 we show that cavity formation is necessarily associated with a unique precursor shock. We also study the bifurcation diagram and do a detailed analysis of the singular asymptotics associated to cavity initiation as a function of the cavity speed of the self-similar profiles. We show that for stress free cavities the critical stretching associated with dynamically cavitating solutions coincides with the critical stretching in the bifurcation diagram of equilibrium elasticity. Our analysis treats both stress-free cavities and cavities with contents.
Directory of Open Access Journals (Sweden)
Sukjung Hwang
2015-11-01
Full Text Available Here we generalize quasilinear parabolic p-Laplacian type equations to obtain the prototype equation $$ u_t - \\hbox{div} \\Big(\\frac{g(|Du|}{|Du|} Du\\Big = 0, $$ where g is a nonnegative, increasing, and continuous function trapped in between two power functions $|Du|^{g_0 -1}$ and $|Du|^{g_1 -1}$ with $1
The global health concept of the German government: strengths, weaknesses, and opportunities.
Bozorgmehr, Kayvan; Bruchhausen, Walter; Hein, Wolfgang; Knipper, Michael; Korte, Rolf; Razum, Oliver; Tinnemann, Peter
2014-01-01
Recognising global health as a rapidly emerging policy field, the German federal government recently released a national concept note for global health politics (July 10, 2013). As the German government could have a significant impact on health globally by making a coherent, evidence-informed, and long-term commitment in this field, we offer an initial appraisal of the strengths, weaknesses, and opportunities for development recognised in this document. We conclude that the national concept is an important first step towards the implementation of a coherent global health policy. However, important gaps were identified in the areas of intellectual property rights and access to medicines. In addition, global health determinants such as trade, economic crises, and liberalisation as well as European Union issues such as the health of migrants, refugees, and asylum seekers are not adequately addressed. Furthermore, little information is provided about the establishment of instruments to ensure an effective inter-ministerial cooperation. Finally, because implementation aspects for the national concept are critical for the success of this initiative, we call upon the newly elected 2013 German government to formulate a global health strategy, which includes a concrete plan of action, a time scale, and measurable goals.
Global solutions through simulation for better decommissioning
International Nuclear Information System (INIS)
Scoto Di Suoccio, Ines; Testard, Vincent
2016-01-01
Decommissioning is a new activity in sense that it only exists a limited experience. Moreover, each facility is different due to their own history and there is no rule about choosing a decommissioning strategy. There are three major decommissioning strategies. First, 'immediate dismantling', which means the action of decommissioning begins immediately after the transfer of waste and nuclear material. Second, 'deferred dismantling strategy', which means that the facility is maintained into a containment zone from thirty to one hundred years before being decommissioned. Finally, 'entombment', means the facility is placed into a reinforced containment until the radionuclides decay and reach a level allowing the site release. When a strategy is decided many factors have to be taken into account. Into a major project such as a reactor decommissioning, there are many smaller projects. The decommissioning strategy can be different among these smaller projects. For some reasons, some entry data are not perfectly known. For example, dosimetric activity has not been updated through time or after specific events. Indeed, because of uncertainties and/or hypothesis existing around projects and their high level of interdependency, global solutions are a good way to choose the best decommissioning strategy. Actually, each entry data has consequences on output results whether it is on costs, cumulated dose, waste or delays. These output data are interdependent and cannot be taken apart from each other. Whether the dose, delays or waste management, all have impact on costs. To obtain an optimal scenario into a special environment, it is necessary to deal with all these items together. This global solution can be implemented thanks to simulation in dedicated software which helps to define the global strategy, to optimize the scenario, and to prevent contingencies. As a complete scenario simulation can be done quickly and efficiently, many strategies can
Sustainable Cities : Local Solutions in the Global South | CRDI ...
International Development Research Centre (IDRC) Digital Library (Canada)
Sustainable Cities : Local Solutions in the Global South. Couverture du livre Sustainable Cities: Local Solutions in the Global South. Directeur(s):. Mélanie Robertson. Maison(s) d'édition: Practical Action Publishing, CRDI. 6 avril 2012. ISBN : 9781853397233. 178 pages. e-ISBN : 9781552505366. Téléchargez le PDF.
[Mechanism of action of combined extremely weak magnetic field on aqueous solution of amino acid].
Zhadin, M N; Bakharev, B V; Bobkova, N V
2014-01-01
The fundamental physical mechanisms of resonance action of an extremely weak (40 nT) alternating magnetic field at the cyclotron frequency combined with a weak (40 μT) static magnetic field, on living systems are analyzed in the present work. The experimental effects of such sort of magnetic fields were described in different papers: the very narrow resonant peaks in electrical conductivity of the aqueous solutions in the in vitro experiments and the biomedical in vivo effects on living animals of magnetic fields with frequencies tuned to some amino acids. The existing experimental in vitro data had a good repeatability in different laboratories and countries. Unfortunately, for free ions such sort of effects are absolutely impossible because the dimensions of an ion rotation radius should be measured by meters at room temperature and at very low static magnetic fields used in all the above experiments. Even for bound ions these effects should be also absolutely impossible from the positions of classic physics because of rather high viscosity of biological liquid media (blood plasma, cerebrospinal liquid, cytoplasm). Only modern quantum electrodynamics of condensed media opens the new ways for solving these problems. The proposed article is devoted to analysis of quantum mechanisms of these effects.
Solution of weakly compressible isothermal flow in landfill gas collection networks
Nec, Y.; Huculak, G.
2017-12-01
Pipe networks collecting gas in sanitary landfills operate under the regime of a weakly compressible isothermal flow of ideal gas. The effect of compressibility has been traditionally neglected in this application in favour of simplicity, thereby creating a conceptual incongruity between the flow equations and thermodynamic equation of state. Here the flow is solved by generalisation of the classic Darcy–Weisbach equation for an incompressible steady flow in a pipe to an ordinary differential equation, permitting continuous variation of density, viscosity and related fluid parameters, as well as head loss or gain due to gravity, in isothermal flow. The differential equation is solved analytically in the case of ideal gas for a single edge in the network. Thereafter the solution is used in an algorithm developed to construct the flow equations automatically for a network characterised by an incidence matrix, and determine pressure distribution, flow rates and all associated parameters therein.
Solution of weakly compressible isothermal flow in landfill gas collection networks
International Nuclear Information System (INIS)
Nec, Y; Huculak, G
2017-01-01
Pipe networks collecting gas in sanitary landfills operate under the regime of a weakly compressible isothermal flow of ideal gas. The effect of compressibility has been traditionally neglected in this application in favour of simplicity, thereby creating a conceptual incongruity between the flow equations and thermodynamic equation of state. Here the flow is solved by generalisation of the classic Darcy–Weisbach equation for an incompressible steady flow in a pipe to an ordinary differential equation, permitting continuous variation of density, viscosity and related fluid parameters, as well as head loss or gain due to gravity, in isothermal flow. The differential equation is solved analytically in the case of ideal gas for a single edge in the network. Thereafter the solution is used in an algorithm developed to construct the flow equations automatically for a network characterised by an incidence matrix, and determine pressure distribution, flow rates and all associated parameters therein. (paper)
Existence of weak solutions to a nonlinear reaction-diffusion system with singular sources
Directory of Open Access Journals (Sweden)
Ida de Bonis
2017-09-01
Full Text Available We discuss the existence of a class of weak solutions to a nonlinear parabolic system of reaction-diffusion type endowed with singular production terms by reaction. The singularity is due to a potential occurrence of quenching localized to the domain boundary. The kind of quenching we have in mind is due to a twofold contribution: (i the choice of boundary conditions, modeling in our case the contact with an infinite reservoir filled with ready-to-react chemicals and (ii the use of a particular nonlinear, non-Lipschitz structure of the reaction kinetics. Our working techniques use fine energy estimates for approximating non-singular problems and uniform control on the set where singularities are localizing.
Changing Foundations for Global Business Systems Solutions
DEFF Research Database (Denmark)
Slepniov, Dmitrij; Wæhrens, Brian Vejrum; Gubi, Ebbe
2011-01-01
Companies are actively seeking new competitive advantages by changing the location and ownership of their manufacturing processes. This process results in increasing fragmentation and dispersion of global business systems of companies. The purpose of this paper is to identify how companies may...... improve the integration of such business systems. The paper draws on a case study of a Danish industrial equipment firm. The paper describes and analyzes the company’s operations network configurations, which lay at the foundations of the company’s global business system. It is demonstrated how...... the operations configurations have been changing over time and affecting the overall business system. The paper identifies the key determinants and outcomes of this change. Moreover, it proposes how the design of operations configurations can be improved through the development of a distinct systemic approach...
Global warming: is weight loss a solution?
Gryka, A; Broom, J; Rolland, C
2012-03-01
The current climate change has been most likely caused by the increased greenhouse gas emissions. We have looked at the major greenhouse gas, carbon dioxide (CO(2)), and estimated the reduction in the CO(2) emissions that would occur with the theoretical global weight loss. The calculations were based on our previous weight loss study, investigating the effects of a low-carbohydrate diet on body weight, body composition and resting metabolic rate of obese volunteers with type 2 diabetes. At 6 months, we observed decreases in weight, fat mass, fat free mass and CO(2) production. We estimated that a 10 kg weight loss of all obese and overweight people would result in a decrease of 49.560 Mt of CO(2) per year, which would equal to 0.2% of the CO(2) emitted globally in 2007. This reduction could help meet the CO(2) emission reduction targets and unquestionably would be of a great benefit to the global health.
Avian Influenza: a global threat needing a global solution
Directory of Open Access Journals (Sweden)
Koh GCH
2008-11-01
Full Text Available Abstract There have been three influenza pandemics since the 1900s, of which the 1919–1919 flu pandemic had the highest mortality rates. The influenza virus infects both humans and birds, and mutates using two mechanisms: antigenic drift and antigenic shift. Currently, the H5N1 avian flu virus is limited to outbreaks among poultry and persons in direct contact to infected poultry, but the mortality rate among infected humans is high. Avian influenza (AI is endemic in Asia as a result of unregulated poultry rearing in rural areas. Such birds often live in close proximity to humans and this increases the chance of genetic re-assortment between avian and human influenza viruses which may produce a mutant strain that is easily transmitted between humans. Once this happens, a global pandemic is likely. Unlike SARS, a person with influenza infection is contagious before the onset of case-defining symptoms which limits the effectiveness of case isolation as a control strategy. Researchers have shown that carefully orchestrated of public health measures could potentially limit the spread of an AI pandemic if implemented soon after the first cases appear. To successfully contain and control an AI pandemic, both national and global strategies are needed. National strategies include source surveillance and control, adequate stockpiles of anti-viral agents, timely production of flu vaccines and healthcare system readiness. Global strategies such as early integrated response, curbing the disease outbreak at source, utilization of global resources, continuing research and open communication are also critical.
Towards automatic global error control: Computable weak error expansion for the tau-leap method
Karlsson, Peer Jesper
2011-01-01
This work develops novel error expansions with computable leading order terms for the global weak error in the tau-leap discretization of pure jump processes arising in kinetic Monte Carlo models. Accurate computable a posteriori error approximations are the basis for adaptive algorithms, a fundamental tool for numerical simulation of both deterministic and stochastic dynamical systems. These pure jump processes are simulated either by the tau-leap method, or by exact simulation, also referred to as dynamic Monte Carlo, the Gillespie Algorithm or the Stochastic Simulation Slgorithm. Two types of estimates are presented: an a priori estimate for the relative error that gives a comparison between the work for the two methods depending on the propensity regime, and an a posteriori estimate with computable leading order term. © de Gruyter 2011.
Very weak solutions to the rotating Stokes, Oseen and Navier–Stokes problems in weighted spaces
Czech Academy of Sciences Publication Activity Database
Kračmar, S.; Krbec, Miroslav; Nečasová, Šárka; Penel, P.; Schumacher, K.
2016-01-01
Roč. 289, 11-12 (2016), s. 1466-1487 ISSN 0025-584X R&D Projects: GA ČR GA13-00522S; GA ČR(CZ) GAP201/11/1304 Institutional support: RVO:67985840 Keywords : viscous incompressible fluid * flow around rotating rigid body * very weak solution * weighted homogenous Sobolev spaces Subject RIV: BA - General Mathematics Impact factor: 0.742, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/ mana .201400052/abstract?systemMessage=Wiley+Online+Library+will+be+unavailable+on+Saturday+3rd+September+2016+at+08.30+BST%2F+03%3A30+EDT%2F+15%3A30+SGT+for+5+hours+and+Sunday+4th+September+at+10%3A00+BST%2F+05%3A00+EST%2F+17%3A00+SGT+for+1+hour++for+essential+maintenance.+Apologies+for+the+inconvenience
Very weak solutions to the rotating Stokes, Oseen and Navier–Stokes problems in weighted spaces
Czech Academy of Sciences Publication Activity Database
Kračmar, S.; Krbec, Miroslav; Nečasová, Šárka; Penel, P.; Schumacher, K.
2016-01-01
Roč. 289, 11-12 (2016), s. 1466-1487 ISSN 0025-584X R&D Projects: GA ČR GA13-00522S; GA ČR(CZ) GAP201/11/1304 Institutional support: RVO:67985840 Keywords : viscous incompressible fluid * flow around rotating rigid body * very weak solution * weighted homogenous Sobolev spaces Subject RIV: BA - General Mathematics Impact factor: 0.742, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/mana.201400052/abstract?systemMessage=Wiley+Online+Library+will+be+unavailable+on+Saturday+3rd+September+2016+at+08.30+BST%2F+03%3A30+EDT%2F+15%3A30+SGT+for+5+hours+ and +Sunday+4th+September+at+10%3A00+BST%2F+05%3A00+EST%2F+17%3A00+SGT+for+1+hour++for+essential+maintenance.+Apologies+for+the+inconvenience
Propolis as a green corrosion inhibitor for bronze in weakly acidic solution
Varvara, Simona; Bostan, Roxana; Bobis, Otilia; Găină, Luiza; Popa, Florin; Mena, Vicente; Souto, Ricardo M.
2017-12-01
In the present work, the inhibitive action of natural propolis on bronze corrosion in a weakly acidic solution containing Na2SO4 and NaHCO3 at pH 5 was evaluated using multiscale electrochemical techniques, namely potentiodynamic polarization, electrochemical impedance spectroscopy and scanning vibrating electrode technique measurements. The major constituents of propolis were identified by HPLC. Surface characterization was performed by SEM-EDX and AFM analysis. Experiments were performed as a function of the propolis concentration and immersion time in the corrosive electrolyte. The obtained results showed that propolis presents good anticorrosive properties on bronze, acting as a mixed-type inhibitor, but its protective effectiveness is time-dependent. The highest inhibiting efficiency of 98.9% was obtained in the presence of 100 ppm propolis, after about 12 h of exposure to inhibitor-containing electrolyte through the stabilization of Cu2O on the bronze surface. The inhibitive properties of propolis on bronze corrosion are likely due to the adsorption of its main constituents (flavonoids and phenolic compounds), through the oxygen atoms in their functional groups and aromatic rings, which have been evidenced by FT-IR spectra. The adsorption of propolis on bronze was found to follow Langmuir adsorption isotherm.
Energy Technology Data Exchange (ETDEWEB)
Schwartz, David Joel [Univ. of California, Berkeley, CA (United States)
1995-07-01
NMR spectroscopy is ideal for studying weak interactions (formation enthalpy ≤20 kcal/mol) in solution. The metallocene bis(pentamethylcyclopentadienyl)ytterbium, Cp*_{2}Yb, is ideal for this purpose. cis-P_{2}PtH_{2}complexes (P = phosphine) were used to produce slow-exchange Cp*_{2}YbL adducts for NMR study. Reversible formation of (P_{2}PtH)_{2} complexes from cis-P_{2}PtH_{2} complexes were also studied, followed by interactions of Cp*_{2}Yb with phosphines, R_{3}PX complexes. A NMR study was done on the interactions of Cp*_{2}Yb with H_{2}, CH_{4}, Xe, CO, silanes, stannanes, C_{6}H_{6}, and toluene.
Global existence of small solutions to semilinear Schroedinger equations
International Nuclear Information System (INIS)
Chihara, Hiroyuki
1996-01-01
We present global existence theorem for semilinear Schrodinger equations. In general, Schrodinger-type equations do not admit the classical energy estimates. To avoid this difficulty, we use S. Doi's method for linear Schrodinger-type equations. Combining his method and L p -L q estimates, we prove the global existence of solutions with small initial data
THE CURRENT GLOBAL CRISIS: CAUSES AND SOLUTIONS
Directory of Open Access Journals (Sweden)
Sabina G. ŢUCA
2013-10-01
Full Text Available In recent years the global economy has been facing a very severe economic and financial crisis. The leading economies of the world are going through a period of deep recession. The aim of this article is to emphasize the causes of the current crisis as well as the measures taken to counteract its effects. In order to achieve this purpose, representative articles on the subject have been analyzed. Compared to other crises, the current crisis is based on totally different causes. That is why the countries affected by the crisis should take unusual measures for the recovery of their economy. However, whatever measures had been already taken, the economic crisis is not over, predictions in this regard being mostly pessimistic.
Chamorro, Diego; Lemarié-Rieusset, Pierre-Gilles; Mayoufi, Kawther
2018-04-01
We study the role of the pressure in the partial regularity theory for weak solutions of the Navier-Stokes equations. By introducing the notion of dissipative solutions, due to D uchon and R obert (Nonlinearity 13:249-255, 2000), we will provide a generalization of the Caffarelli, Kohn and Nirenberg theory. Our approach sheels new light on the role of the pressure in this theory in connection to Serrin's local regularity criterion.
Steady-state analysis of the nickel oxide in neutral and weakly alkaline solutions
International Nuclear Information System (INIS)
Albu, C.; Deconinck, D.; Hotoiu, L.; Deconinck, J.; Topa, V.
2013-01-01
Thin passive nickel oxides are investigated in neutral and weakly alkaline pH solutions under steady-state conditions. The chemical species considered in the oxide film are nickel interstitials and vacancies, as well as oxygen vacancies. The set of differential equations used in this study is solved using the finite element method (FEM) and is able to reproduce the experimental data present in the literature. Steady-state oxide thickness variation with the applied electrode potential presents a linear behavior with an average slope of 2 nm/V. The role of dominant species in these thin films is investigated in terms of current density produced by the reactions at the interfaces, the reactions involving production and consumption of Ni 2+ vacancies playing a major role in the steady-state properties of the oxide. We show that the mass transport of species in the oxide is influenced more by the migration component of the flux than the diffusion component. Our results also show that the flux of Ni 2+ vacancies is approximately two orders of magnitude higher than the flux of oxygen vacancies and Ni 2+ interstitials, making them the dominant defects in the oxide (thus the p-type electronic character is present). Also, the Ni 2+ vacancies were found to have density levels of 10 20 –10 21 cm −3 close to the metal–film interface. Variations of the steady-state thickness and logarithm of the current density with the electrolyte pH, show a linear increase and decrease respectively. Some of these results are compared with data from experiments and simulations done on the iron oxide, showing that Ni forms steady-state passive films that are thinner than the ones formed on Fe under the same environment conditions (pH, temperature, and applied potential)
Weak Solutions to the One-dimensional Non-Isentropic Gas Dynamics by the Vanishing Viscosity Method
Directory of Open Access Journals (Sweden)
Kazufumi Ito
1996-06-01
Full Text Available equations of gas dynamics with the entropy preserved. Equations are formulated so that the problem is reduced into the 2 by 2 system of conservation laws with a forcing term in momentum equation. The method of compensated compactness is then applied to prove the existence of weak solution in the vanishing viscosity method.
A note on local interior regularity of a suitable weak solution to the Navier--Stokes problem
Czech Academy of Sciences Publication Activity Database
Neustupa, Jiří
2013-01-01
Roč. 6, č. 5 (2013), s. 1391-1400 ISSN 1937-1632 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : Navier-Stokes equations * suitable weak solution * regularity Subject RIV: BA - General Mathematics http://aimsciences.org/journals/displayArticlesnew.jsp?paperID=8344
Directory of Open Access Journals (Sweden)
Wang Li
2008-01-01
Full Text Available We investigate the existence of almost-periodic weak solutions of second-order neutral delay-differential equations with piecewise constant argument of the form , where denotes the greatest integer function, is a real nonzero constant, and is almost periodic.
Czech Academy of Sciences Publication Activity Database
Neustupa, Jiří; Penel, P.
2014-01-01
Roč. 46, č. 2 (2014), s. 1681-1700 ISSN 0036-1410 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : Navier-Stokes equations * weak solution * regularity criteria Subject RIV: BA - General Mathematics Impact factor: 1.265, year: 2014 http://epubs.siam.org/doi/abs/10.1137/120874874
Zhao, Xiaopeng; Zhu, Mingxuan
2018-04-01
In this paper, we consider the small initial data global well-posedness of solutions for the magnetohydrodynamics with Hall and ion-slip effects in R^3. In addition, we also establish the temporal decay estimates for the weak solutions. With these estimates in hand, we study the algebraic time decay for higher-order Sobolev norms of small initial data solutions.
Existence of positive radial solutions for a weakly coupled system via blow up
Directory of Open Access Journals (Sweden)
Marta García-Huidobro
1998-01-01
Full Text Available The existence of positive solutions to certain systems of ordinary differential equations is studied. Particular forms of these systems are satisfied by radial solutions of associated partial differential equations.
Connolly, Brian D.; Petry, Chris; Yadav, Sandeep; Demeule, Barthélemy; Ciaccio, Natalie; Moore, Jamie M.R.; Shire, Steven J.; Gokarn, Yatin R.
2012-01-01
Weak protein-protein interactions are thought to modulate the viscoelastic properties of concentrated antibody solutions. Predicting the viscoelastic behavior of concentrated antibodies from their dilute solution behavior is of significant interest and remains a challenge. Here, we show that the diffusion interaction parameter (kD), a component of the osmotic second virial coefficient (B2) that is amenable to high-throughput measurement in dilute solutions, correlates well with the viscosity of concentrated monoclonal antibody (mAb) solutions. We measured the kD of 29 different mAbs (IgG1 and IgG4) in four different solvent conditions (low and high ion normality) and found a linear dependence between kD and the exponential coefficient that describes the viscosity concentration profiles (|R| ≥ 0.9). Through experimentally measured effective charge measurements, under low ion normality where the electroviscous effect can dominate, we show that the mAb solution viscosity is poorly correlated with the mAb net charge (|R| ≤ 0.6). With this large data set, our results provide compelling evidence in support of weak intermolecular interactions, in contrast to the notion that the electroviscous effect is important in governing the viscoelastic behavior of concentrated mAb solutions. Our approach is particularly applicable as a screening tool for selecting mAbs with desirable viscosity properties early during lead candidate selection. PMID:22828333
The global nursing faculty shortage: status and solutions for change.
Nardi, Deena A; Gyurko, Charlene C
2013-09-01
In addition to a global shortage of nurses, there is also a shortage of academically qualified faculty available to teach in schools of nursing. A systematic review examined proposed solutions to the global shortage of nursing faculty. Metasynthesis was used to compare and critically appraise strategies offered for solving or ameliorating the global nursing faculty shortage by premier nursing organizations. 181 recommendations in 62 publications were categorized into eight major themed solutions, including centralizing data management, international collaboration in nursing research, and increased funding for full-time faculty positions in nursing programs. The nursing faculty shortage is due to a confluence of factors, including the global migration of nurses, a seeming persistent devaluation of faculty by academic programs, disincentives, and an overall reduction in full-time equivalent faculty positions. Results point to a needed change in direction and approach to solving the nursing faculty shortage. By designing new education models that fit global healthcare needs and pooling teaching resources, designing and using the same databases across organizations to track and project faculty needs, and collaborating between schools and businesses to create mutually beneficial agreements for services, nursing faculty capacity can be enhanced, and nursing's capacity to meet global healthcare needs can be expanded. The results of this systematic review can be used as a rubric for the design and development of strategies to end the nursing faculty shortage and expand global nursing capacity. © 2013 Sigma Theta Tau International.
Hydroxyl radical induced ultra-weak photon emission from tyrosine solutions
Czech Academy of Sciences Publication Activity Database
Bereta, M.; Cifra, Michal; Červinková, Kateřina; Janoušek, L.; Barabas, J.
2015-01-01
Roč. 17, č. 4 (2015), s. 3-7 ISSN 1335-4205 R&D Projects: GA ČR GP13-37368P Institutional support: RVO:67985882 Keywords : Reactive oxygen species * Ultra-weak photon emission * Hydroxyl radical Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering
Weak solutions for nonlinear fractional differential equations on reflexive Banach spaces
Directory of Open Access Journals (Sweden)
Mouffak Benchohra
2010-09-01
Full Text Available The aim of this paper is to investigate a class of boundary value problem for fractional differential equations involving nonlinear integral conditions. The main tool used in our considerations is the technique associated with measures of weak noncompactness.
Directory of Open Access Journals (Sweden)
Mouffak Benchohra
2012-01-01
Full Text Available The aim of this paper is to investigate a class of boundary value problems for fractional differential equations involving nonlinear integral conditions. The main tool used in our considerations is the technique associated with measures of weak noncompactness.
Uniform in Time Description for Weak Solutions of the Hopf Equation with Nonconvex Nonlinearity
Directory of Open Access Journals (Sweden)
Antonio Olivas Martinez
2009-01-01
Full Text Available We consider the Riemann problem for the Hopf equation with concave-convex flux functions. Applying the weak asymptotics method we construct a uniform in time description for the Cauchy data evolution and show that the use of this method implies automatically the appearance of the Oleinik E-condition.
Czech Academy of Sciences Publication Activity Database
Neustupa, Jiří; Penel, P.
2012-01-01
Roč. 350, 11-12 (2012), s. 597-602 ISSN 1631-073X R&D Projects: GA ČR GA201/08/0012 Institutional support: RVO:67985840 Keywords : Navier-Stokes equations * weak solution * regularity Subject RIV: BA - General Mathematics Impact factor: 0.477, year: 2012 http://www.sciencedirect.com/science/article/pii/S1631073X12001926#
Czech Academy of Sciences Publication Activity Database
Nečasová, Šárka; Takahashi, T.; Tucsnak, M.
2011-01-01
Roč. 116, č. 3 (2011), s. 329-352 ISSN 0167-8019 R&D Projects: GA ČR(CZ) GAP201/11/1304 Institutional research plan: CEZ:AV0Z10190503 Keywords : Navier-Stokes equations * fluid-structure integration * weak solutions * free boundary Subject RIV: BA - General Mathematics Impact factor: 0.899, year: 2011 http://rd.springer.com/article/10.1007/s10440-011-9646-2#
Czech Academy of Sciences Publication Activity Database
Dell'Oro, Filippo; Feireisl, Eduard
2015-01-01
Roč. 128, November (2015), s. 136-148 ISSN 0362-546X R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : compressible Navier - Stokes equations * unbounded domain * weak solutions * energy inequality Subject RIV: BA - General Mathematics Impact factor: 1.125, year: 2015 http://www.sciencedirect.com/science/article/pii/S0362546X15002692
Czech Academy of Sciences Publication Activity Database
Dell'Oro, Filippo; Feireisl, Eduard
2015-01-01
Roč. 128, November (2015), s. 136-148 ISSN 0362-546X R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : compressible Navier-Stokes equations * unbounded domain * weak solutions * energy inequality Subject RIV: BA - General Mathematics Impact factor: 1.125, year: 2015 http://www.sciencedirect.com/science/article/pii/S0362546X15002692
Bresch, D.; Huang, X.
2011-08-01
This paper mainly concerns the mathematical justification of a viscous compressible multi-fluid model linked to the Baer-Nunziato model used by engineers, see for instance I shii (Thermo-fluid dynamic theory of two-phase flow, Eyrolles, Paris, 1975), under a "stratification" assumption. More precisely, we show that some approximate finite-energy weak solutions of the isentropic compressible Navier-Stokes equations converge, on a short time interval, to the strong solution of this viscous compressible multi-fluid model, provided the initial density sequence is uniformly bounded with corresponding Young measures which are linear convex combinations of m Dirac measures. To the authors' knowledge, this provides, in the multidimensional in space case, a first positive answer to an open question, see H illairet (J Math Fluid Mech 9:343-376, 2007), with a stratification assumption. The proof is based on the weak solutions constructed by D esjardins (Commun Partial Differ Equ 22(5-6):977-1008, 1997) and on the existence and uniqueness of a local strong solution for the multi-fluid model established by H illairet assuming initial density to be far from vacuum. In a first step, adapting the ideas from H off and S antos (Arch Ration Mech Anal 188:509-543, 2008), we prove that the sequence of weak solutions built by D esjardins has extra regularity linked to the divergence of the velocity without any relation assumption between λ and μ. Coupled with the uniform bound of the density property, this allows us to use appropriate defect measures and their nice properties introduced and proved by H illairet (Aspects interactifs de la m'ecanique des fluides, PhD Thesis, ENS Lyon, 2005) in order to prove that the Young measure associated to the weak limit is the convex combination of m Dirac measures. Finally, under a non-degeneracy assumption of this combination ("stratification" assumption), this provides a multi-fluid system. Using a weak-strong uniqueness argument, we prove that
Parikh, Tapan; Sandhu, Harpreet K; Talele, Tanaji T; Serajuddin, Abu T M
2016-06-01
The purpose of this study was to develop an amorphous solid dispersion (SD) of an extremely water-insoluble and very weakly basic drug, itraconazole (ITZ), by interaction with weak organic acids and then drying that would enhance dissolution rate of drug and physical stability of formulation. Aqueous solubility of ITZ in concentrated solutions of weak organic acids, such as glutaric, tartaric, malic and citric acid, was determined. Solutions with high drug solubility were dried using vacuum oven and the resulting SDs having 2 to 20% drug load were characterized by differential scanning calorimetry (DSC), powder X-ray diffractometry (PXRD) and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. The dissolution of SDs was initially studied in 250 mL of 0.1 N HCl (pH 1.1), and any undissolved solids were collected and analyzed by PXRD. The pH of the dissolution medium was then changed from 1.1 to 5.5, particle size of precipitates were measured, and drug concentrations in solution were determined by filtration through membrane filters of varying pore sizes. The aqueous solubility of ITZ was greatly enhanced in presence of weak acids. While the solubility of ITZ in water was ~4 ng/ mL, it increased to 25-40 mg per g of solution at 25°C and 200 mg per g of solution at 65°C at a high acid concentration leading to extremely high solubilization. PXRD of SDs indicated that ITZ was present in the amorphous form, wherein the acid formed a partially crystalline matrix. ATR-FTIR results showed possible weak interactions, such as hydrogen bonding, between drug and acid but there was no salt formation. SDs formed highly supersaturated solutions at pH 1.1 and had superior dissolution rate as compared to amorphous drug and physical mixtures of drug and acids. Following the change in pH from 1.1 to 5.5, ITZ precipitated as mostly nanoparticles, providing high surface area for relatively rapid redissolution. A method of highly solubilizing an
Directory of Open Access Journals (Sweden)
Kamonrat Sombut
2013-01-01
Full Text Available The purpose of this paper is to introduce an iterative algorithm for finding a common element of the set of fixed points of quasi-nonexpansive mappings and the solution of split feasibility problems (SFP and systems of equilibrium problems (SEP in Hilbert spaces. We prove that the sequences generated by the proposed algorithm converge weakly to a common element of the fixed points set of quasi-nonexpansive mappings and the solution of split feasibility problems and systems of equilibrium problems under mild conditions. Our main result improves and extends the recent ones announced by Ceng et al. (2012 and many others.
Barker, T.
2018-03-01
The main subject of this paper concerns the establishment of certain classes of initial data, which grant short time uniqueness of the associated weak Leray-Hopf solutions of the three dimensional Navier-Stokes equations. In particular, our main theorem that this holds for any solenodial initial data, with finite L_2(R^3) norm, that also belongs to certain subsets of {it{VMO}}^{-1}(R^3). As a corollary of this, we obtain the same conclusion for any solenodial u0 belonging to L2(R^3)\\cap \\dot{B}^{-1+3/p}_{p,∞}(R^3), for any 3Navier-Stokes equations, with these classes of initial data. Such properties seem to be of independent interest. Consequently, we are also able to show if a weak Leray-Hopf solution u satisfies certain extensions of the Prodi-Serrin condition on R^3 × ]0,T[, then it is unique on R^3 × ]0,T[ amongst all other weak Leray-Hopf solutions with the same initial value. In particular, we show this is the case if u\\in L^{q,s}(0,T; L^{p,s}(R^3)) or if it's L^{q,∞}(0,T; L^{p,∞}(R^3)) norm is sufficiently small, where 3
Li, Chang-Hai; Si, Peng-Fei
2005-01-01
Experiments for single and bisolute competitive adsorption were carried out to investigate the adsorption behavior of beta-naphthalenesulfonic acid (NSA) and sulfuric acid (H2SO4) from their solution at 25 degrees C onto weakly basic resin D301R. Adsorption affinity of sulfuric acid on D301R was found to be much higher than that of NSA. The data of single-solute adsorption were fitted to the Langmuir model and the Freundlich adsorption model. The ideal adsorbed solution theory (IAST) coupled with the single-solute adsorption models were used to predict the bisolute competitive adsorption equilibria. The IAST coupled with the Langmuir and the Freundlich model for sulfuric acid and NSA, respectively, yields the favorable representation of the bisolute competitive adsorption behavior.
Applications of on-line weak affinity interactions in free solution capillary electrophoresis
DEFF Research Database (Denmark)
Heegaard, Niels H H; Nissen, Mogens H; Chen, David D Y
2002-01-01
enantiomers and on using capillary electrophoresis to characterize such interactions quantitatively. We describe the equations for binding isotherms, illustrate how selectivity can be manipulated by varying the additive concentrations, and show how the methods may be used to estimate binding constants. On......The impressive selectivity offered by capillary electrophoresis can in some cases be further increased when ligands or additives that engage in weak affinity interactions with one or more of the separated analytes are added to the electrophoresis buffer. This on-line affinity capillary...... electrophoresis approach is feasible when the migration of complexed molecules is different from the migration of free molecules and when separation conditions are nondenaturing. In this review, we focus on applying weak interactions as tools to enhance the separation of closely related molecules, e.g., drug...
Global solution for a chemotactic haptotactic model of cancer invasion
Tao, Youshan; Wang, Mingjun
2008-10-01
This paper deals with a mathematical model of cancer invasion of tissue recently proposed by Chaplain and Lolas. The model consists of a reaction-diffusion-taxis partial differential equation (PDE) describing the evolution of tumour cell density, a reaction-diffusion PDE governing the evolution of the proteolytic enzyme concentration and an ordinary differential equation modelling the proteolysis of the extracellular matrix (ECM). In addition to random motion, the tumour cells are directed not only by haptotaxis (cellular locomotion directed in response to a concentration gradient of adhesive molecules along the ECM) but also by chemotaxis (cellular locomotion directed in response to a concentration gradient of the diffusible proteolytic enzyme). In one space dimension, the global existence and uniqueness of a classical solution to this combined chemotactic-haptotactic model is proved for any chemotactic coefficient χ > 0. In two and three space dimensions, the global existence is proved for small χ/μ (where μ is the logistic growth rate of the tumour cells). The fundamental point of proof is to raise the regularity of a solution from L1 to Lp (p > 1). Furthermore, the existence of blow-up solutions to a sub-model in two space dimensions for large χ shows, to some extent, that the condition that χ/μ is small is necessary for the global existence of a solution to the full model.
The primary solution of global poor health and poverty.
Tegegne, Ayalew
2008-01-01
There is a huge global burden of disease and mortality. The principal underlying cause is regarded as poverty. This is associated with a global order of fear, over-consumption, over-population and violence, which can interact in a vicious circle. It is proposed that the solution to the problem is not only the relief of poverty, but the institution of a new order in which the individual is sovereign. This in turn requires a trinity of ideals for the individual: self-control to avoid over-consumption, altruism to cope with fear, and peace to manage violence.
Inner Peace and Global Harmony: Individual Wellbeing and Global Solutions in the Art of Living
Directory of Open Access Journals (Sweden)
Stephen Jacobs
2014-10-01
Full Text Available his paper explores the discourse in the Art of Living (AOL, a Hindu derived transnational meditation movement, which suggests that solutions to global problems are best addressed at the individual level. Ethnographic fieldwork, qualita-tive interviews and an analysis of published material suggest that the primary concern of the AOL is the reduction of stress and anxiety for the individual practitioner. This reduction of stress not only means that the individual practitioner develops ‘inner peace', but also contributes to global harmony. AOL is an exemplar of ‘therapeutic solutions', which are characterized by disillusionment with estab-lished institutions and a quest for inner meaning. AOL articulates this therapeutic solution, not only in terms of narcissistic needs, but links this quest for inner meaning to wider social and global concerns.
International Nuclear Information System (INIS)
Robinson, James C; Sadowski, Witold
2009-01-01
We show that if u is a suitable weak solution of the unforced three-dimensional Navier–Stokes equations corresponding to a divergence-free initial condition in H 1/2 (Ω), then the Lagrangian trajectory through almost every initial condition in Ω is unique for all t ≥ 0. This is a corollary of two subsidiary results: (i) if S is the singular set of some suitable weak solution of the three-dimensional Navier–Stokes equations for which p in L 5/3 (Ω × (0, T)) (such solutions are known to exist), then for any compact subset K of Ω × (0, T) the upper box-counting dimension of S intersection K is no larger than 5/3 and (ii) for a volume-preserving flow in R n arising from a vector field in L 1 (0, T; L ∞ ), trajectories through almost every initial condition avoid any set whose box-counting dimension is strictly less than n − 1. The result (i) is new, although it requires only a small variation of an argument contained in Caffarelli et al (1982 Commun. Pure Appl. Math. 35 771–831) and we give a simple geometric proof of (ii), a result originally proved by Aizenmann using other methods (1978 Duke Math. J. 45 809–12)
The Building of Weak Expertise: The Work of Global University Rankers
Lim, Miguel Antonio
2018-01-01
University rankers are the subject of much criticism, and yet they remain influential in the field of higher education. Drawing from a two-year field study of university ranking organizations, interviews with key correspondents in the sector, and an analysis of related documents, I introduce the concept of "weak expertise." This kind of…
Directory of Open Access Journals (Sweden)
Chuanyi Zhang
2008-06-01
Full Text Available We investigate the existence of almost-periodic weak solutions of second-order neutral delay-differential equations with piecewise constant argument of the form (x(t+x(tÃ¢ÂˆÂ’1Ã¢Â€Â²Ã¢Â€Â²=qx(2[(t+1/2]+f(t, where [Ã¢Â‹Â…] denotes the greatest integer function, q is a real nonzero constant, and f(t is almost periodic.
Stormy weather: 101 solutions to global climate change
International Nuclear Information System (INIS)
Dauncey, G.; Mazza, P.
2001-01-01
This book provides a comprehensive guide to energy efficiency measures that would rid the world of the threat of global warming caused by the wasteful use of hydrocarbon fuels and the resulting greenhouse gas emissions. The actions to be taken are not directed to governments and industry alone; indeed, the change must involve every segment of society to be effective. Accordingly, the book recommends actions that could be taken by individuals, citizen organizations, municipalities, businesses and organizations, energy companies, automobile companies, states and provinces, national governments, developing nations and global solutions. The recommendations range from choosing energy efficient appliances and buying green power, through increased recycling, reuse and reduced consumption, building solar and other renewable energy capacity, using sustainable fuels in automobiles, introducing tax measures favouring energy efficiency and sustainable development, to launching macro-level plans for a global green deal, establishing a global climate fund, accelerating the phase-out of CHCs, HCFCs and HFCs, forming a global ecological alliance and declaring a century of ecological restoration. Bibliographic notes, illustrations
The Building of Weak Expertise: the Work of Global University Rankers
Lim, Miguel Antonio
2017-01-01
University rankers are much criticized and yet remain influential in the field of higher education. Drawing from a two-year field study of university ranking organizations, interviews with key correspondents in the sector, and an analysis of related documents, I introduce the concept of weak expertise. This kind of expertise is the result of a constantly negotiated balance between the relevance, reliability, and robustness of rankers’ data and their relationships with their key readers and au...
Neutrons for global energy solutions. Book of abstracts
Energy Technology Data Exchange (ETDEWEB)
NONE
2010-07-01
The book of abstracts of the conference on neutrons for global energy solutions include contributions to the following topics: Views from politics: What do we need in European energy research: cooperation, large facilities, more science? Fundamental research for energy supply. View from the United States. View from industry: Neutrons for nuclear reactor development in transition stage between generation III and generation IV. Toyotas's expectations for neutron analysis. Instrumentation and cross cutting issues. Energy sources. Waste management and environment. Li ion batteries. Photovoltaics. Savings and catalysis. Fuel cells. Hydrogen storage.
Global solutions of nonlinear Schrödinger equations
Bourgain, J
1999-01-01
This volume presents recent progress in the theory of nonlinear dispersive equations, primarily the nonlinear Schrödinger (NLS) equation. The Cauchy problem for defocusing NLS with critical nonlinearity is discussed. New techniques and results are described on global existence and properties of solutions with large Cauchy data. Current research in harmonic analysis around Strichartz's inequalities and its relevance to nonlinear PDE is presented. Several topics in NLS theory on bounded domains are reviewed. Using the NLS as an example, the book offers comprehensive insight on current research r
Impact of LEO satellites on global GPS solutions
Rothacher, M.; Svehla, D.
2003-04-01
Already at present quite a few Low Earth Orbiting (LEO) satellites (SAC-C, CHAMP, JASON-1, GRACE-1 and GRACE-2) are equipped with one or more GPS receivers for precise orbit determination or other applications (atmospheric sounding, gravity field recovery, ...). This trend will continue in the near future (e.g., with the GOCE and COSMIC missions) and we will soon have an entire``constellation´´ of LEO satellites tracked by GPS at our disposal. In this contribution we study the impact of LEO GPS measurements (from a single LEO satellite or from a LEO constellation) on global GPS solutions, where GPS satellite orbits and clocks, Earth rotation parameters (ERPs), station coordinates and troposphere zenith delays are determined simultaneously. In order to assess the impact of the LEO GPS data on global IGS results, we perform a combined analysis of the space-borne and the ground-based GPS data. Such a combination may benefit on one hand from the differences between a ground station and a LEO, namely, (1) the different tracking geometry (coverage of isolated geographical areas by LEOs, rapidly changing geometry, ...); (2) that LEOs connect all ground stations within 1-2 hours; (3) that baselines between LEO and ground stations may be longer than station-station baselines; (4) that no tropospheric delays have to be estimated for LEOs; and (5) that LEOs orbit the Earth within the ionosphere and may therefore contribute to global ionosphere models. On the other hand we have to deal with difficult aspects of precise orbit determination for the LEOs: only if we succeed to obtain very accurate dynamic or reduced-dynamic orbits for the LEOs, we will have a chance to improve the global GPS results at all. We present first results concerning the influence of LEO data on GPS orbits, ERPs, site coordinates, and troposphere zenith delays using both, variance-covariance analyses based on simulated data and combined global solutions based on real CHAMP and JASON data and the data
International Nuclear Information System (INIS)
Bechlars, J.
1978-12-01
1) Integrable (L 1 ) singularities, occuring on the boundary or along the diagonal direction, and jumps along the diagonal direction do not disturb the compactness of otherwise continuous integral operator kernels. So the theory of compact operators can be applied for solving the integral equation. 2) Provided the regular parts of the kernel are sufficiently differentiable, the continuous differentiability (Cn) of the right hand side is transposed to the solution, if the kernel has no singularities or no singularities on the boundary and no jump. In the case of singularities in connection with a jump examples show, that this result is not valid in general. Therefore a second definition of smoothness has been introduced (Csup((n,α)) : continuous differentiability in the interior and 'limitation of derivatives') which can be applied in such cases and on the other side shows satisfactory error behaviour during interpolation and includes singularities from logarithms and negative powers. Provided diagonal singularities or singularities on the boundary can be asigned to Csup((n+1,α-1)) (0 2 also Csup((2,α)) (0 -2 ). This is confirmed by numerical examples. (orig./HSI) [de
Mensi, Walid; Tiwari, Aviral Kumar; Yoon, Seong-Min
2017-04-01
This paper estimates the weak-form efficiency of Islamic stock markets using 10 sectoral stock indices (basic materials, consumer services, consumer goods, energy, financials, health care, industrials, technology, telecommunication, and utilities). The results based on the multifractal detrended fluctuation analysis (MF-DFA) approach show time-varying efficiency for the sectoral stock markets. Moreover, we find that they tend to show high efficiency in the long term but moderate efficiency in the short term, and that these markets become less efficient after the onset of the global financial crisis. These results have several significant implications in terms of asset allocation for investors dealing with Islamic markets.
Global weak solutions to a class of non-Newtonian compressible fluids
Czech Academy of Sciences Publication Activity Database
Feireisl, Eduard; Liao, X.; Málek, J.
2015-01-01
Roč. 38, č. 16 (2015), s. 3482-3494 ISSN 0170-4214 Keywords : compressible fluid * generalized Newtonian fluids * power law fluid Subject RIV: BA - General Mathematics Impact factor: 1.002, year: 2015 http://onlinelibrary.wiley.com/doi/10.1002/mma.3432/abstract
Global existence for weak solutions of the Cauchy problem in a model of radiation hydrodynamics
Czech Academy of Sciences Publication Activity Database
Ducomet, B.; Nečasová, Šárka
2014-01-01
Roč. 420, č. 1 (2014), s. 464-482 ISSN 0022-247X R&D Projects: GA ČR GAP201/10/1920; GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : Cauchy problem * Navier-Stokes-Fourier system * radiation hydrodynamics Subject RIV: BA - General Mathematics Impact factor: 1.120, year: 2014 http://www.sciencedirect.com/science/article/pii/S0022247X14004855
International Nuclear Information System (INIS)
Zeng, Huihui
2015-01-01
In this paper we establish the global existence of smooth solutions to vacuum free boundary problems of the one-dimensional compressible isentropic Navier–Stokes equations for which the smoothness extends all the way to the boundaries. The results obtained in this work include the physical vacuum for which the sound speed is C 1/2 -Hölder continuous near the vacuum boundaries when 1 < γ < 3. The novelty of this result is its global-in-time regularity which is in contrast to the previous main results of global weak solutions in the literature. Moreover, in previous studies of the one-dimensional free boundary problems of compressible Navier–Stokes equations, the Lagrangian mass coordinates method has often been used, but in the present work the particle path (flow trajectory) method is adopted, which has the advantage that the particle paths and, in particular, the free boundaries can be traced. (paper)
Directory of Open Access Journals (Sweden)
Nikolay N. Nefedov
2018-01-01
Full Text Available In the paper, we study a singularly perturbed periodic in time problem for the parabolic reaction-advection-diffusion equation with a weak linear advection. The case of the reactive term in the form of a cubic nonlinearity is considered. On the basis of already known results, a more general formulation of the problem is investigated, with weaker sufficient conditions for the existence of a solution with an internal transition layer to be provided than in previous studies. For convenience, the known results are given, which ensure the fulfillment of the existence theorem of the contrast structure. The justification for the existence of a solution with an internal transition layer is based on the use of an asymptotic method of differential inequalities based on the modification of the terms of the constructed asymptotic expansion. Further, sufficient conditions are established to fulfill these requirements, and they have simple and concise formulations in the form of the algebraic equation w(x0,t = 0 and the condition wx(x0,t < 0, which is essentially a condition of simplicity of the root x0(t and ensuring the stability of the solution found. The function w is a function of the known functions appearing in the reactive and advective terms of the original problem. The equation w(x0,t = 0 is a problem for finding the zero approximation x0(t to determine the localization region of the inner transition layer. In addition, the asymptotic Lyapunov stability of the found periodic solution is investigated, based on the application of the so-called compressible barrier method. The main result of the paper is formulated as a theorem.
Konovalov, Dmitry A.; Cocks, Daniel G.; White, Ronald D.
2017-10-01
The velocity distribution function and transport coefficients for charged particles in weakly ionized plasmas are calculated via a multi-term solution of Boltzmann's equation and benchmarked using a Monte-Carlo simulation. A unified framework for the solution of the original full Boltzmann's equation is presented which is valid for ions and electrons, avoiding any recourse to approximate forms of the collision operator in various limiting mass ratio cases. This direct method using Lebedev quadratures over the velocity and scattering angles avoids the need to represent the ion mass dependence in the collision operator through an expansion in terms of the charged particle to neutral mass ratio. For the two-temperature Burnett function method considered in this study, this amounts to avoiding the need for the complex Talmi-transformation methods and associated mass-ratio expansions. More generally, we highlight the deficiencies in the two-temperature Burnett function method for heavy ions at high electric fields to calculate the ion velocity distribution function, even though the transport coefficients have converged. Contribution to the Topical Issue "Physics of Ionized Gases (SPIG 2016)", edited by Goran Poparic, Bratislav Obradovic, Dragana Maric and Aleksandar Milosavljevic.
Pazur, Alexander
2004-01-01
Background Previous reports indicate altered metabolism and enzyme kinetics for various organisms, as well as changes of neuronal functions and behaviour of higher animals, when they were exposed to specific combinations of weak static and alternating low frequency electromagnetic fields. Field strengths and frequencies, as well as properties of involved ions were related by a linear equation, known as the formula of ion cyclotron resonance (ICR, abbreviation mentioned first by Liboff). Under certain conditions already a aqueous solution of the amino acid and neurotransmitter glutamate shows this effect. Methods An aqueous solution of glutamate was exposed to a combination of a static magnetic field of 40 μT and a sinusoidal electromagnetic magnetic field (EMF) with variable frequency (2–7 Hz) and an amplitude of 50 nT. The electric conductivity and dielectric properties of the solution were investigated by voltammetric techniques in combination with non linear dielectric spectroscopy (NLDS), which allow the examination of the dielectric properties of macromolecules and molecular aggregates in water. The experiments target to elucidate the biological relevance of the observed EMF effect on molecular level. Results An ion cyclotron resonance (ICR) effect of glutamate previously reported by the Fesenko laboratory 1998 could be confirmed. Frequency resolution of the sample currents was possible by NLDS techniques. The spectrum peaks when the conditions for ion cyclotron resonance (ICR) of glutamate are matched. Furthermore, the NLDS spectra are different under ICR- and non-ICR conditions: NLDS measurements with rising control voltages from 100–1100 mV show different courses of the intensities of the low order harmonics, which could possibly indicate "intensity windows". Furthermore, the observed magnetic field effects are pH dependent with a narrow optimum around pH 2.85. Conclusions Data will be discussed in the context with recent published models for the
International Nuclear Information System (INIS)
Bjorken, J.D.
1978-01-01
Weak interactions are studied from a phenomenological point of view, by using a minimal number of theoretical hypotheses. Charged-current phenomenology, and then neutral-current phenomenology are discussed. This all is described in terms of a global SU(2) symmetry plus an electromagnetic correction. The intermediate-boson hypothesis is introduced and lower bounds on the range of the weak force are inferred. This phenomenology does not yet reconstruct all the predictions of the conventional SU(2)xU(1) gauge theory. To do that requires an additional assumption of restoration of SU(2) symmetry at asymptotic energies
Big Data Solution for CTBT Monitoring Using Global Cross Correlation
Gaillard, P.; Bobrov, D.; Dupont, A.; Grenouille, A.; Kitov, I. O.; Rozhkov, M.
2014-12-01
from the primary IMS stations. In this talk, we will present the Master Event algorithm and the associated workflow, we will give an overview of the designed technical solutions (from the building blocks to the global infrastructure), and we will show the preliminary results at a regional scale.
Neustupa, Tomáš
2017-07-01
The paper presents the mathematical model of a steady 2-dimensional viscous incompressible flow through a radial blade machine. The corresponding boundary value problem is studied in the rotating frame. We provide the classical and weak formulation of the problem. Using a special form of the so called "artificial" or "natural" boundary condition on the outflow, we prove the existence of a weak solution for an arbitrarily large inflow.
2013-01-18
... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] Eco Global Corporation, Execute Sports, Inc., FacePrint Global Solutions, Inc., FinancialContent, Inc., and Firstgold Corp.; Order of Suspension of... current and accurate information concerning the securities of Eco Global Corporation because it has not...
Min, Stephen K; Samaranayake, Chaminda P; Sastry, Sudhir K
2011-05-26
Direct measurements of reaction volume, so far, have been limited to atmospheric pressure. This study describes a method for in situ reaction volume measurements under pressure using a variable volume piezometer. Reaction volumes for protonic ionization of weak acid buffering agents (MES, citric acid, sulfanilic acid, and phosphoric acid) were measured in situ under pressure up to 400 MPa at 25 °C. The methodology involved initial separation of buffering agents within the piezometer using gelatin capsules. Under pressure, the volume of the reactants was measured at 25 °C, and the contents were heated to 40 °C to dissolve the gelatin and allow the reaction to occur, and cooled to 25 °C, where the volume of products was measured. Reaction volumes were used to calculate pH of the buffer solutions as a function of pressure. The results show that the measured reaction volumes as well as the calculated pH values generally quite agree with their respective theoretically predicted values up to 100 MPa. The results of this study highlight the need for a comprehensive theory to describe the pressure behavior of ionization reactions in realistic systems especially at higher pressures.
Energy Technology Data Exchange (ETDEWEB)
Mikulic, L. [Mercedes Car Group, DaimlerChrysler AG, Mercedes-Benz Technology Center, Stuttgart (Germany); Lee, R. [DaimlerChrysler Corporation, Auburn Hills, MI (United States)
2007-07-01
'Globalization' - few concepts have shaped the last fifteen years like this has. For some it is a synonym for unexpected economic and social revolution, a threatening change in familiar arrangements, whilst others see the coalescence of global structures as, more than anything, a challenge - which, if mastered, offers endless possibilities for success. The challenges facing an automotive manufacturer in a globalized world are of quite a different nature. Not least, the constantly increasing competitive pressure has reduced the number of independent automotive manufacturers, in what is known as the Triad (Europe, Japan and North America), from 42 at the beginning of the 1960's to just 15 today. Also in Europe, consolidation has led, on the one hand, to a reduction in individual brands and on the other, to a number of collaborative projects between companies. Even in the dynamically growing East Asia markets, where the number of independent carmakers is still large, such collaborations have already occurred. In the near future much dynamics can be expected within the two fastest growing markets, China and India. Within these competitive markets, a globally operating company like DaimlerChrysler is faced with new challenges. (orig.)
Czech Academy of Sciences Publication Activity Database
Neustupa, Jiří
2014-01-01
Roč. 139, č. 4 (2014), s. 685-698 ISSN 0862-7959 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : Navier-Stokes equation * suitable weak solution * regularity Subject RIV: BA - General Mathematics http://hdl.handle.net/10338.dmlcz/144145
Global structure of static spherically symmetric solutions surrounded by quintessence
Cruz, Miguel; Ganguly, Apratim; Gannouji, Radouane; Leon, Genly; Saridakis, Emmanuel N.
2017-06-01
We investigate all static spherically symmetric solutions in the context of general relativity surrounded by a minimally-coupled quintessence field, using dynamical system analysis. Applying the 1 + 1 + 2 formalism and introducing suitable normalized variables involving the Gaussian curvature, we were able to reformulate the field equations as first order differential equations. In the case of a massless canonical scalar field we recovered all known black hole results, such as the Fisher solution, and we found that apart from the Schwarzschild solution all other solutions are naked singularities. Additionally, we identified the symmetric phase space which corresponds to the white hole part of the solution and in the case of a phantom field, we were able to extract the conditions for the existence of wormholes and define all possible classes of solutions such as cold black holes, singular spacetimes and wormholes such as the Ellis wormhole, for example. For an exponential potential, we found that the black hole solution which is asymptotically flat is unique and it is the Schwarzschild spacetime, while all other solutions are naked singularities. Furthermore, we found solutions connecting to a white hole through a maximum radius, and not a minimum radius (throat) such as wormhole solutions, therefore violating the flare-out condition. Finally, we have found a necessary and sufficient condition on the form of the potential to have an asymptotically AdS spacetime along with a necessary condition for the existence of asymptotically flat black holes.
The global nephrology workforce: emerging threats and potential solutions!
Sharif, Muhammad U; Elsayed, Mohamed E; Stack, Austin G
2016-02-01
Amidst the rising tide of chronic kidney disease (CKD) burden, the global nephrology workforce has failed to expand in order to meet the growing healthcare needs of this vulnerable patient population. In truth, this shortage of nephrologists is seen in many parts of the world, including North America, Europe, Australia, New Zealand, Asia and the African continent. Moreover, expert groups on workforce planning as well as national and international professional organizations predict further reductions in the nephrology workforce over the next decade, with potentially serious implications. Although the full impact of this has not been clearly articulated, what is clear is that the delivery of care to patients with CKD may be threatened in many parts of the world unless effective country-specific workforce strategies are put in place and implemented. Multiple factors are responsible for this apparent shortage in the nephrology workforce and the underpinning reasons may vary across health systems and countries. Potential contributors include the increasing burden of CKD, aging workforce, declining interest in nephrology among trainees, lack of exposure to nephrology among students and residents, rising cost of medical education and specialist training, increasing cultural and ethnic disparities between patients and care providers, increasing reliance on foreign medical graduates, inflexible work schedules, erosion of nephrology practice scope by other specialists, inadequate training, reduced focus on scholarship and research funds, increased demand to meet quality of care standards and the development of new care delivery models. It is apparent from this list that the solution is not simple and that a comprehensive evaluation is required. Consequently, there is an urgent need for all countries to develop a policy framework for the provision of kidney disease services within their health systems, a framework that is based on accurate projections of disease burden, a
The global nephrology workforce: emerging threats and potential solutions!
Sharif, Muhammad U.; Elsayed, Mohamed E.; Stack, Austin G.
2016-01-01
Amidst the rising tide of chronic kidney disease (CKD) burden, the global nephrology workforce has failed to expand in order to meet the growing healthcare needs of this vulnerable patient population. In truth, this shortage of nephrologists is seen in many parts of the world, including North America, Europe, Australia, New Zealand, Asia and the African continent. Moreover, expert groups on workforce planning as well as national and international professional organizations predict further reductions in the nephrology workforce over the next decade, with potentially serious implications. Although the full impact of this has not been clearly articulated, what is clear is that the delivery of care to patients with CKD may be threatened in many parts of the world unless effective country-specific workforce strategies are put in place and implemented. Multiple factors are responsible for this apparent shortage in the nephrology workforce and the underpinning reasons may vary across health systems and countries. Potential contributors include the increasing burden of CKD, aging workforce, declining interest in nephrology among trainees, lack of exposure to nephrology among students and residents, rising cost of medical education and specialist training, increasing cultural and ethnic disparities between patients and care providers, increasing reliance on foreign medical graduates, inflexible work schedules, erosion of nephrology practice scope by other specialists, inadequate training, reduced focus on scholarship and research funds, increased demand to meet quality of care standards and the development of new care delivery models. It is apparent from this list that the solution is not simple and that a comprehensive evaluation is required. Consequently, there is an urgent need for all countries to develop a policy framework for the provision of kidney disease services within their health systems, a framework that is based on accurate projections of disease burden, a
Fujita, Ken-ichi; Kawahara, Ryoko; Aikawa, Takuya; Yamaguchi, Ryohei
2015-07-27
An efficient catalytic system for the production of hydrogen from a methanol-water solution has been developed using a new anionic iridium complex bearing a functional bipyridonate ligand as a catalyst. This system can be operated under mild conditions [weakly basic solution (0.046 mol L(-1) NaOH) below 100 °C] without the use of an additional organic solvent. Long-term continuous hydrogen production from a methanol-water solution catalyzed by the anionic iridium complex was also achieved. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Weak solutions for the dynamic equations $x^{\\Delta(m}(t = f (t; x(t$ on time scales
Directory of Open Access Journals (Sweden)
Aneta Sikorska-Nowak
2014-05-01
\\end{equation*} where $x^{(\\Delta m}$ denotes a weak $m$-th order $\\Delta$-derivative, $T$ denotes an unbounded time scale (nonempty closed subset of R such that there exists a sequence $(a_n $ in $T$ and $a_n \\to \\infty $, $E$ is a Banach space and $f$ is weakly -- weakly sequentially continuous and satisfies some conditions expressed in terms of measures of weak noncompactness. The Sadovskii fixed point theorem and Ambrosetti's lemma are used to prove the main result. As dynamic equations are a unification of differential and difference equations our result is also valid for differential and difference equations. The results presented in this paper are new not only for Banach valued functions but also for real valued functions.
Positive global solutions for a general model of size-dependent population dynamics
Kato, Nobuyuki
2000-01-01
We study size-structured population models of general type which have the growth rate depending on the size and time. The local existence and uniqueness of the solution have been shown by Kato and Torikata (1997). Here, we discuss the positivity of the solution and global existence as well as $L^\\infty$ solutions.
Positive global solutions for a general model of size-dependent population dynamics
Directory of Open Access Journals (Sweden)
Nobuyuki Kato
2000-01-01
have the growth rate depending on the size and time. The local existence and uniqueness of the solution have been shown by Kato and Torikata (1997. Here, we discuss the positivity of the solution and global existence as well as L ∞ solutions.
Existence of global solutions to reaction-diffusion systems via a Lyapunov functional
Directory of Open Access Journals (Sweden)
Said Kouachi
2001-10-01
Full Text Available The purpose of this paper is to construct polynomial functionals (according to solutions of the coupled reaction-diffusion equations which give $L^{p}$-bounds for solutions. When the reaction terms are sufficiently regular, using the well known regularizing effect, we deduce the existence of global solutions. These functionals are obtained independently of work done by Malham and Xin [11].
Liato, Viacheslav; Hammami, Riadh; Aïder, Mohammed
2017-06-01
The aim of this work was to study the potential of diluted electro-activated solutions of weak organic acid salts (potassium acetate, potassium citrate and calcium lactate) to extend the shelf life of blueberries during post-harvest storage. The sanitizing capacity of these solutions was studied against pathogenic bacteria Listeria monocytogenes and E. coli O157:H7 as well as phytopathogenic fungi A. alternata, F. oxysporum and B. cinerea. The results showed that a 5-min treatment of inoculated blueberries with electro-activated solutions resulted in a 4 log CFU/g reduction in Listeria monocytogenes for all solutions. For E. coli O157:H7, the electro-activated potassium acetate and potassium citrate solutions achieved a decrease of 3.5 log CFU/g after 5 min of berry washing. The most important fungus reduction was found when blueberries were washed with an electro-activated solution of potassium acetate and a NaOCl solution. After 5 min of blueberry washing with an electro-activated potassium acetate solution, a very high reduction effect was observed for A. alternata, F. oxysporum and B. cinerea, which showed survival levels of only 2.2 ± 0.16, 0.34 ± 0.15 and 0.21 ± 0.16 log CFU/g, respectively. Regarding the effect of the washing on the organoleptic quality of blueberries, the obtained results showed no negative effect on the product color or textural profile. Finally, this work suggests that washing with electro-activated solutions of weak organic acid salts can be used to enhance the shelf-life of blueberries during post-harvest storage. Copyright Â© 2016 Elsevier Ltd. All rights reserved.
Czech Academy of Sciences Publication Activity Database
Fojtíková, Lucia; Kristeková, M.; Málek, Jiří; Sokos, E.; Csicsay, K.; Zahradník, J.
2016-01-01
Roč. 20, č. 1 (2016), 93-106 ISSN 1383-4649 R&D Projects: GA ČR GAP210/12/2336 Institutional support: RVO:67985891 Keywords : Focal-mechanism uncertainty * Little Carpathians * Relative location uncertainty * Seismic network * Uncertainty mapping * Waveform inversion * Weak earthquakes Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.089, year: 2016
Compact solutions to the equation T x= y T x= y T x= y in a weakly ...
Indian Academy of Sciences (India)
Given two vectors , in a Hilbert space and a weakly closed T ( N ) -module U , we provide a necessary and sufficient condition for the existence of a compact operator in U satisfying T x = y . Author Affiliations. Dong Zhe1 Jiang Hai-Yi1. Department of Mathematics, Zhejiang University, Hangzhou 310027, People's ...
Nonlinear initial-value problems with positive global solutions
Directory of Open Access Journals (Sweden)
John V. Baxley
2003-02-01
Full Text Available We give conditions on $m(t$, $p(t$, and $f(t,y,z$ so that the nonlinear initial-value problem {gather*} frac{1}{m(t} (p(ty'' + f(t,y,p(ty' = 0,quadmbox{for }t>0, y(0=0,quad lim_{t o 0^+} p(ty'(t = B, end{gather*} has at least one positive solution for all $t>0$, when $B$ is a sufficiently small positive constant. We allow a singularity at $t=0$ so the solution $y'(t$ may be unbounded near $t=0$.
Sustainable Cities: Local Solutions in the Global South | IDRC ...
International Development Research Centre (IDRC) Digital Library (Canada)
2012-04-06
Apr 6, 2012 ... A sustainable urban future for all requires raising the quality of life of the most vulnerable. Existing at the margins of urban life, low-income residents of cities in the global South are subject to numerous environmental burdens and are too often excluded from mainstream development and planning. In the ...
The neglect of global oral health: symptoms and solutions
Benzian, H.
2014-01-01
This thesis presents a sequence of papers to illustrate selected aspects of the neglect of global oral health, highlights new approaches to describing the extent and impact of dental caries, explains the difficulties related to quality assurance of fluoride toothpastes; and, finally, describes a
About Global Stable of Solutions of Logistic Equation with Delay
Kaschenko, S. A.; Loginov, D. O.
2017-12-01
The article is devoted to the definition of all the arguments for which all positive solutions of logistic equation with delay tend to zero for t → ∞. The authors have proved the acquainted Wright’s conjecture on evaluation of a multitude of such arguments. An approach that enables subsequent refinement of this evaluation has been developed.
Global seafood markets : challenges and solutions for consumers
Ferrito, Venera; 4th International Congress on Biodiversity. “Man, Natural Habitats and Euro-Mediterranean Biodiversity”
2017-01-01
Human activities in and around the oceans are affecting the health of ocean ecosystems. In particular, the exploitation of natural resources such as fishing, likely has the greatest anthropogenic impact on the world’s marine ecosystems. Global fish landings decreased in the last 50 years in all countries due to continuous overfishing. Indeed, in the major fishing areas, as fishing intensity increased, catch per unit area of fishing effort has correspondingly decreased.
Pazur, Alexander
2004-01-01
Background Previous reports indicate altered metabolism and enzyme kinetics for various organisms, as well as changes of neuronal functions and behaviour of higher animals, when they were exposed to specific combinations of weak static and alternating low frequency electromagnetic fields. Field strengths and frequencies, as well as properties of involved ions were related by a linear equation, known as the formula of ion cyclotron resonance (ICR, abbreviation mentioned first by Liboff). Under...
Managing Economic Solution for a global sustainable Development
Dumitrescu, Luigi; Mihaescu, Liviu; Mihaescu, DIiana
2010-01-01
We live in an imperfect world. The poverty, the disease, the lack of education, the environmental destruction, the energy crisis, the overpopulation, the increasing consumption of resources, the deforestation and desertification, the biodiversity loss, the pollution, the emissions of greenhouse gases, the climate change, water supply, human violence etc. are all current issues. What can be done to provide adequate solutions to these problems? How to respond to these issues?
Haddad, L. H.; Carr, Lincoln D.
2015-11-01
We analyze the vortex solution space of the (2+1)-dimensional nonlinear Dirac equation for bosons in a honeycomb optical lattice at length scales much larger than the lattice spacing. Dirac point relativistic covariance combined with s-wave scattering for bosons leads to a large number of vortex solutions characterized by different functional forms for the internal spin and overall phase of the order parameter. We present a detailed derivation of these solutions which include skyrmions, half-quantum vortices, Mermin-Ho and Anderson-Toulouse vortices for vortex winding {\\ell }=1. For {\\ell }≥slant 2 we obtain topological as well as non-topological solutions defined by the asymptotic radial dependence. For arbitrary values of ℓ the non-topological solutions include bright ring-vortices which explicitly demonstrate the confining effects of the Dirac operator. We arrive at solutions through an asymptotic Bessel series, algebraic closed-forms, and using standard numerical shooting methods. By including a harmonic potential to simulate a finite trap we compute the discrete spectra associated with radially quantized modes. We demonstrate the continuous spectral mapping between the vortex and free particle limits for all of our solutions.
International Nuclear Information System (INIS)
Liu Haifei; Wang Li
2006-01-01
In this Letter, by using the inequality method and the Lyapunov functional method, we analyze the globally exponential stability and the existence of periodic solutions of a class of cellular neutral networks with delays and variable coefficients. Some simple and new sufficient conditions ensuring the existence and uniqueness of globally exponential stability of periodic solutions for cellular neutral networks with variable coefficients and delays are obtained. In addition, one example is also worked out to illustrate our theory
Karande, B. D.
2014-12-01
In this paper, we discuss the existence of solutions for a nonlinear functional integral equation of fractional order in R+ via a hybrid fixed point theorem due to B.C. Dhage. This equation will be carried out in the Banach space of real functions defined, continuous and bounded on an unbounded interval R+. Moreover, we show that solutions of this equation are uniformly globally attractive and uniformly globally asymptotically attractive on R+.
Energy Technology Data Exchange (ETDEWEB)
Liu Haifei [School of Management and Engineering, Nanjing University, Nanjing 210093 (China)]. E-mail: hfliu80@126.com; Wang Li [School of Management and Engineering, Nanjing University, Nanjing 210093 (China)
2006-09-15
In this Letter, by using the inequality method and the Lyapunov functional method, we analyze the globally exponential stability and the existence of periodic solutions of a class of cellular neutral networks with delays and variable coefficients. Some simple and new sufficient conditions ensuring the existence and uniqueness of globally exponential stability of periodic solutions for cellular neutral networks with variable coefficients and delays are obtained. In addition, one example is also worked out to illustrate our theory.
Contemporary Business Education: a Solution for Global Leadership Challenges
Directory of Open Access Journals (Sweden)
Tudor Cristian Ţiclău
2014-08-01
Full Text Available Education and professional development is considered central issues in civil service development and public administration reform. While this may be true, the content of such programs bears equal influence in skill acquirement, which in turn, has an impact on managerial performance (Perry, 1989. The contemporary economic and social environment poses numerous and complex challenges to public leaders, who need to be equipped with the adequate set of skills and competencies in order to have a proper response. The present paper aims to find out the whether the current educational programs from the business field can be a solution for preparing the next generation of public (and private leaders. My argument is that the latest developments in public management reform (New Public Management, Good Governance and Public Entrepreneurship combined with new demands for effectiveness, efficiency and high quality public services could increase the relevance of such programs. In support for this I presented a series of research results that point to a set of common leadership challenges that transcend the public-private divide. Finally I explored the offerings of the top 5 MBA programs in the world to see whether this is reflected in their educational programs. Not surprisingly, three out of the five programs analysed offer dual degree programs that combine business and public management education as a solution for the leadership challenges that lay ahead.
New childcare solution helps CERN’s global community
CERN Bulletin
2011-01-01
Commuting between the home institute and CERN is a tough task for a lot of scientists with families. However, thanks to a newly signed agreement between CERN and the “Jardin de Capucine” kindergarten, the task of looking for a childcare solution might turn out to be easier than originally expected: 4 places are reserved for all categories of CERN personnel for child enrolment periods that can vary between a few weeks and a few months. Le Jardin de Capucine. CERN already has a well-established on-site kindergarten but the community is growing and the need for childcare is constantly increasing. In order to find a viable solution to the problem, CERN's Director-General, Rolf Heuer, signed an agreement with "Le Jardin de Zébulon" in January this year for the provision of 40 places at the "Jardin de Capucine", a new private crèche that opened this autumn. The agreement became fully operational on 2 November,...
2010-06-16
... Employment and Training Administration Trueheat, Inc., a Subsidiary of Global Heating Solutions, Inc... Global Heating Solutions, Inc., Currently Known as Truheat, a Division of Three Heat LLC, Allegan, MI..., applicable to workers of TrueHeat, Inc., a subsidiary of Global Heating Solutions, Inc., Allegan, Michigan...
Alfimov, A. V.; Aryslanova, E. M.; Chivilikhin, S. A.
2016-08-01
The present paper is devoted to the theoretical study of the morphology of nanocrystals formed through self-assembly of amphoteric oxide colloidal nanoparticles in weak electrolytes. A mathematical model of multi-particle colloidal interaction was developed within the framework of the Derjaguin, Landau, Verwey, Overbeak (DLVO) theory. This model accounts for the surface charge regulation during the multi-particle interaction and reveals the presence of orientation effects during nanoparticle aggregation. These effects are presumed to affect the morphology of the self-assembled nanocrystals and may present the means of controlling the structure of synthesised nanomaterials.
2011-03-14
... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-74,326] Pitney Bowes, Inc., Mailing Solutions Management, Global Engineering Group, Including On-Site Leased Workers From Guidant... workers and former workers of Pitney Bowes, Inc., Mailing Solutions Management Division, Engineering...
Decay estimate of global solutions to the generalized double dispersion model in Morrey spaces
Wang, Yu-Zhu; Gu, Liuxin; Wang, Yinxia
2017-08-01
In this paper, we investigate the initial value problem for the generalized double dispersion model in Morrey spaces. Based on the decay properties of the solution operator in Morrey spaces, global existence and decay estimates of solutions are proved by Banach fixed point theorem.
Technology solutions for a global business. Opportunities and challenges
Energy Technology Data Exchange (ETDEWEB)
Warren, Tim
2000-07-01
Shell's relationship with Norway goes back a long way and is very important to our future as well, as is evident from this presentation, which describes some of the pressures on a global energy business like Shell. It also deals with the fundamental importance of technology in the way we respond to those pressures. The power of innovation, and of partnerships, in keeping us at the front of the wave and, using our experiences, it is described how we at Shell deal with these issues. It also gives some examples of the benefits that have come out of our partnerships here in Norway, and the challenges and opportunities confronting those partnerships in the future.
Global existence of solutions to the Cauchy problem for time-dependent Hartree equations
International Nuclear Information System (INIS)
Chadam, J.M.; Glassey, R.T.
1975-01-01
The existence of global solutions to the Cauchy problem for time-dependent Hartree equations for N electrons is established. The solution is shown to have a uniformly bounded H 1 (R 3 ) norm and to satisfy an estimate of the form two parallel PSI (t) two parallel/sub H 2 ; less than or equal to c exp(kt). It is shown that ''negative energy'' solutions do not converge uniformly to zero as t → infinity. (U.S.)
Directory of Open Access Journals (Sweden)
Shengmao Fu
2010-01-01
Full Text Available We study a cubic predator-prey system with stage structure for the prey. This system is a generalization of the two-species Lotka-Volterra predator-prey model. Firstly, we consider the asymptotical stability of equilibrium points to the system of ordinary differential equations type. Then, the global existence of solutions and the stability of equilibrium points to the system of weakly coupled reaction-diffusion type are discussed. Finally, the existence of nonnegative classical global solutions to the system of strongly coupled reaction-diffusion type is investigated when the space dimension is less than 6, and the global asymptotic stability of unique positive equilibrium point of the system is proved by constructing Lyapunov functions.
Bardeau, S.; Soucail, G.; Kneib, J.-P.; Czoske, O.; Ebeling, H.; Hudelot, P.; Smail, I.; Smith, G. P.
Aims. We present a wide-field multi-color survey of a homogeneous sample of eleven clusters of galaxies for which we measure total masses and mass distributions from weak lensing. This sample, spanning a small range in both X-ray luminosity and redshift, is ideally suited to determining the
Jenichen, Anne; Schapper, Andrea
2017-01-01
The purpose of this article is to investigate in which ways multi-level actor cooperation advances national and local implementation processes of human rights norms in weak-state contexts. Examining the cases of women’s rights in Bosnia and Herzegovina and children’s rights in Bangladesh, we comparatively point to some advantages and disadvantages cooperative relations between international organisations, national governments and local NGOs can entail. Whereas these multi-level actor constell...
Nuclear energy - the global solution for sustainable development in Romania
International Nuclear Information System (INIS)
Gorea, Valica; Popescu, Dan; Cristescu, Catalin
2006-01-01
The global population growth of the planet during the next 50 years will be accompanied by a dramatic increase in the demand for energy. Almost two-thirds of the world's population today has no access to electricity in developing countries. Without energy, the entire infrastructure would collapse: agriculture, transportation, waste collection. Developing and industrialized nations alike must address - both individually and collectively - how they can achieve sustainable growth. To date about 16 % of the world's electricity is produced by 443 reactors in 31 countries. They have a combined total capacity of 362 GW of electricity and produced a combined total of 2618 TWh in 2004, according to the International Atomic Energy Agency statistics. These reactors produce electricity for their respective countries safely, reliably and with the lowest environmental impact of any major energy source. Nuclear power provides steady energy at a consistent price without competing for resources from other countries. Some deficient in fossil fuels large countries (like France) rely on nuclear power up to about 80 % of their power necessities. United States (US) has the greatest number of commercial reactors in operation, but the share of nuclear power doesn't exceed 20 %, because of their abundant oil resources. On a percentage basis, Romania is one of the smaller users of nuclear energy. In Romania, according to the official data of the Romanian Ministry of Economy and Trade, nuclear energy share is only 10% of the gross power generation structure, with 5.560 GWh during the year 2004. Construction of the first unit of the Nuclear Power Plant (NPP) Cernavoda started in 1980 and of units 2-5 in 1982. Unit 1 was connected to the grid in mid of 1996 and entered commercial operation in December 1996. The state nuclear power corporation, Societatea Nationala Nuclearelectrica (SNN), established in 1998, operates Cernavoda NPP. Its capacity factor has averaged over 86 % so far and
Accounting for Government in the Global South: do Global Solutions Match Local Problems?
Directory of Open Access Journals (Sweden)
Stewart Lawrence
2009-06-01
Full Text Available This paper examines the impact of globalised accounting and economic reforms on the public sectors of lessdeveloped countries. Our interest is in the international institutions that have been instrumental inintroducing common, global remedies which appear to be based on theoretical understandings as opposed toexperience of the effects of their interventions. A growing concern is being expressed about suchinterventions, but there is a sparcity of reports from the field. We argue that a re-think is required of type ofthe public sector financial management reforms which the international financial institutions and the nationalaid agencies have been promoting across the Global South for the last decade or so.
Rehren, K. -H.
1996-01-01
Weak C* Hopf algebras can act as global symmetries in low-dimensional quantum field theories, when braid group statistics prevents group symmetries. Possibilities to construct field algebras with weak C* Hopf symmetry from a given theory of local observables are discussed.
On the Existence of a Weak Solution of a Half-Cell Model for PEM Fuel Cells
Directory of Open Access Journals (Sweden)
Shuh-Jye Chern
2010-01-01
Full Text Available A nonlinear boundary value problem (BVP from the modelling of the transport phenomena in the cathode catalyst layer of a one-dimensional half-cell single-phase model for proton exchange membrane (PEM fuel cells, derived from the 3D model of Zhou and Liu (2000, 2001, is studied. It is a BVP for a system of three coupled ordinary differential equations of second order. Schauder's fixed point theorem is applied to show the existence of a solution in the Sobolev space 1.
Minasian, Sarkis M; Galagudza, Michael M; Dmitriev, Yuri V; Kurapeev, Dmitry I; Vlasov, Timur D
2013-04-02
The Krebs-Henseleit buffer is the best perfusion solution for isolated mammalian hearts. We hypothesized that a Krebs-Henseleit buffer-based cardioplegic solution might provide better myocardial protection than well-known crystalloid cardioplegic solutions because of its optimal electrolyte and glucose levels, presence of buffer systems, and mild hyperosmolarity. Isolated Langendorff-perfused rat hearts were subjected to either global ischemia without cardioplegia (controls) or cardioplegic arrest for either 60 or 180 min, followed by 120 min of reperfusion. The modified Krebs-Henseleit buffer-based cardioplegic solution (mKHB) and St. Thomas' Hospital solution No. 2 (STH2) were studied. During global ischemia, the temperatures of the heart and the cardioplegic solutions were maintained at either 37°C (60 min of ischemia) or 22°C (moderate hypothermia, 180 min of ischemia). Hemodynamic parameters were registered throughout the experiments. The infarct size was determined through histochemical examination. Cardioplegia with the mKHB solution at moderate hypothermia resulted in a minimal infarct size (5 ± 3%) compared to that in the controls and STH2 solution (35 ± 7% and 19 ± 9%, respectively; P Krebs-Henseleit buffer-based cardioplegic might be superior to the standard crystalloid solution (STH2).
International Nuclear Information System (INIS)
Martin, Valerie; Seguin-Jacques, Catherine; Aulas, Camille
2017-12-01
Content: - Focus: A global initiative for efficient solutions. On 14 November, during COP23, ADEME officially joined the World Alliance for Efficient Solutions, an initiative launched by the Solar Impulse Foundation. - Expertise: Energy: an industrial sector in transition. At a time when reducing energy consumption and improving energy efficiency seem to be essential to the development of a sustainable and competitive industry, electrical load management has emerged as a promising solution. - Worldwide: Ivory Coast: promoting sustainable construction. From 18 to 20 September, ADEME took part in two events held in Abidjan dedicated to sustainable construction in the Ivory Coast, a subject in which the Agency had a long-standing experience to share at the heart of the Global Alliance for Building and Construction (Global ABC)
An Iterated Global Mascon Solution with Focus on Land Ice Mass Evolution
Luthcke, S. B.; Sabaka, T.; Rowlands, D. D.; Lemoine, F. G.; Loomis, B. D.; Boy, J. P.
2012-01-01
Land ice mass evolution is determined from a new GRACE global mascon solution. The solution is estimated directly from the reduction of the inter-satellite K-band range rate observations taking into account the full noise covariance, and formally iterating the solution. The new solution increases signal recovery while reducing the GRACE KBRR observation residuals. The mascons are estimated with 10-day and 1-arc-degree equal area sampling, applying anisotropic constraints for enhanced temporal and spatial resolution of the recovered land ice signal. The details of the solution are presented including error and resolution analysis. An Ensemble Empirical Mode Decomposition (EEMD) adaptive filter is applied to the mascon solution time series to compute timing of balance seasons and annual mass balances. The details and causes of the spatial and temporal variability of the land ice regions studied are discussed.
The impact of climate change on the global wine industry: Challenges & solutions
Directory of Open Access Journals (Sweden)
Michelle Renée Mozell
2014-12-01
Full Text Available This paper explores the impact of climate change upon the global production of winegrapes and wine. It includes a review of the literature on the cause and effects of climate change, as well as illustrations of the specific challenges global warming may bring to the production of winegrapes and wine. More importantly, this paper provides some practical solutions that industry professionals can take to mitigate and adapt to the coming change in both vineyards and wineries.
The impact of climate change on the global wine industry: Challenges & solutions
Mozell, Michelle Renée; Thach, Liz
2014-01-01
This paper explores the impact of climate change upon the global production of winegrapes and wine. It includes a review of the literature on the cause and effects of climate change, as well as illustrations of the specific challenges global warming may bring to the production of winegrapes and wine. More importantly, this paper provides some practical solutions that industry professionals can take to mitigate and adapt to the coming change in both vineyards and wineries.
Wang, Yu-Zhu; Wei, Changhua
2018-04-01
In this paper, we investigate the initial value problem for the generalized double dispersion equation in R^n. Weighted decay estimate and asymptotic profile of global solutions are established for n≥3 . The global existence result was already proved by Kawashima and the first author in Kawashima and Wang (Anal Appl 13:233-254, 2015). Here, we show that the nonlinear term plays an important role in this asymptotic profile.
Pan, Ronghua; Zhou, Yi; Zhu, Yi
2018-02-01
In this paper, we study the global existence of classical solutions to the three dimensional incompressible viscous magneto-hydrodynamical system without magnetic diffusion on periodic boxes, that is, with periodic boundary conditions. We work in Eulerian coordinates and employ a time-weighted energy estimate to prove the global existence result, under the assumptions that the initial magnetic field is close enough to an equilibrium state and the initial data have some symmetries.
Global solution to the 3D inhomogeneous nematic liquid crystal flows with variable density
Hu, Xianpeng; Liu, Qiao
2018-04-01
In this paper, we investigate the global existence and uniqueness of solution to the 3D inhomogeneous incompressible nematic liquid crystal flows with variable density in the framework of Besov spaces. It is proved that there exists a global and unique solution to the nematic liquid crystal flows if the initial data (ρ0 - 1 ,u0 ,n0 -e3) ∈ M (B˙p,1 3/p - 1 (R3)) × B˙p,1 3/p - 1 (R3) × B˙p,1 3/p (R3) with 1 ≤ p < 6, and satisfies
Hydrogen as a renewable and sustainable solution in reducing global fossil fuel consumption
International Nuclear Information System (INIS)
Midilli, Adnan; Dincer, Ibrahim
2008-01-01
In this paper, hydrogen is considered as a renewable and sustainable solution for reducing global fossil fuel consumption and combating global warming and studied exergetically through a parametric performance analysis. The environmental impact results are then compared with the ones obtained for fossil fuels. In this regard, some exergetic expressions are derived depending primarily upon the exergetic utilization ratios of fossil fuels and hydrogen: the fossil fuel based global waste exergy factor, hydrogen based global exergetic efficiency, fossil fuel based global irreversibility coefficient and hydrogen based global exergetic indicator. These relations incorporate predicted exergetic utilization ratios for hydrogen energy from non-fossil fuel resources such as water, etc., and are used to investigate whether or not exergetic utilization of hydrogen can significantly reduce the fossil fuel based global irreversibility coefficient (ranging from 1 to +∞) indicating the fossil fuel consumption and contribute to increase the hydrogen based global exergetic indicator (ranging from 0 to 1) indicating the hydrogen utilization at a certain ratio of fossil fuel utilization. In order to verify all these exergetic expressions, the actual fossil fuel consumption and production data are taken from the literature. Due to the unavailability of appropriate hydrogen data for analysis, it is assumed that the utilization ratios of hydrogen are ranged between 0 and 1. For the verification of these parameters, the variations of fossil fuel based global irreversibility coefficient and hydrogen based global exergetic indicator as the functions of fossil fuel based global waste exergy factor, hydrogen based global exergetic efficiency and exergetic utilization of hydrogen from non-fossil fuels are analyzed and discussed in detail. Consequently, if exergetic utilization ratio of hydrogen from non-fossil fuel sources at a certain exergetic utilization ratio of fossil fuels increases
Directory of Open Access Journals (Sweden)
Minoru Tabata
2016-01-01
Full Text Available We study the initial-value problem for the replicator equation of the N-region Core-Periphery model in spatial economics. The main result shows that if workers are sufficiently agglomerated in a region at the initial time, then the initial-value problem has a unique global solution that converges to the equilibrium solution expressed by full agglomeration in that region.
On global attractivity of solutions of a functional-integral equation
Directory of Open Access Journals (Sweden)
Mohamed Darwish
2007-10-01
Full Text Available We prove an existence theorem for a quadratic functional-integral equation of mixed type. The functional-integral equation studied below contains as special cases numerous integral equations encountered in nonlinear analysis. With help of a suitable measure of noncompactness, we show that the functional integral equation of mixed type has solutions being continuous and bounded on the interval $[0,\\infty$ and those solutions are globally attractive.
Global existence and decay of solutions of the Cauchy problem in thermoelasticity with second sound
Kasimov, Aslan R.
2013-06-04
We consider the one-dimensional Cauchy problem in non-linear thermoelasticity with second sound, where the heat conduction is modelled by Cattaneo\\'s law. After presenting decay estimates for solutions to the linearized problem, including refined estimates for data in weighted Lebesgue-spaces, we prove a global existence theorem for small data together with improved decay estimates, in particular for derivatives of the solutions. © 2013 Taylor & Francis.
2013-07-12
... Technology Solutions Central Security Services Dresher, Pennsylvania; TA-W-82,634A, Prudential Global Business Technology Solutions Central Security Services Iselin, New Jersey; TA-W-82,634B, Prudential Global Business Technology Solutions Central Security Services Plymouth, Minnesota; TA- W-82,634C, Prudential...
Jacobson, M. Z.
2015-12-01
Three major global problems of our times are global warming, air pollution mortality and morbidity, and energy insecurity. Whereas, policy makers with the support of the public must implement solutions to these problems, it is scientists and engineers who are best equipped to evaluate technically sound, optimal, and efficient solutions. Yet, a disconnect exists between information provided by scientists and engineers and policies implemented. Part of the reason is that scientific information provided to policy makers and the public is swamped out by information provided by lobbyists and another part is the difficulty in providing information to the hundreds of millions of people who need it rather than to just a few thousand. What other ways are available, aside from issuing press releases on scientific papers, for scientists to disseminate information? Three growing methods are through social media, creative media, and storytelling. The Solutions Project is a non-profit non-governmental organization whose goal is to bring forth scientific information about 100% clean, renewable energy plans to the public, businesses, and policy makers using these and related tools. Through the use of social media, the development of engaging internet and video content, and storytelling, the group hopes to increase the dissemination of information for social good. This talk discusses the history and impacts to date of this group and its methods. Please see www.thesolutionsproject.org and 100.org for more information.
The absence of global positive solutions of systems of semilinear elliptic inequalities in cones
International Nuclear Information System (INIS)
Laptev, G G
2000-01-01
Let K be a cone in R N , N>=2. We establish conditions for the absence of global non-trivial non-negative solutions of semilinear elliptic inequalities and systems of inequalities of the form -div(|x| α Du)>=|x| β u q , u| ∂K =0. We find the critical exponent q* that divides the domains of existence of these solutions from those of their absence. We prove that in the limiting case q=q* there are no solutions. The method is to multiply the system by a special factor and integrate the inequalities thus obtained
A global numerical solution of the radial Schroedinger equation by second-order perturbation theory
International Nuclear Information System (INIS)
Adam, G.
1979-01-01
A global numerical method, which uses second-order perturbation theory, is described for the solution of the radial Schroedinger equation. The perturbative numerical (PN) solution is derived in two stages: first, the original potential is approximated by a piecewise continuous parabolic function, and second, the resulting Schroedinger equation is solved on each integration step by second-order perturbation theory, starting with a step function reference approximation for the parabolic potential. We get a manageable PN algorithm, which shows an order of accuracy equal to six in the solution of the original Schroedinger equation, and is very stable against round off errors. (author)
Bajpai, Shailendra; Gupta, S K; Dey, Apurba; Jha, M K; Bajpai, Vidushi; Joshi, Saurabh; Gupta, Arvind
2012-08-15
In this paper, response surface methodology (RSM) approach using Central Composite Design (CCD) is applied to develop mathematical model and optimize process parameters for Cr (VI) removal from aqueous streams using weakly anionic resin Amberlite IRA 96. The individual and combined effect of four process parameters, i.e. contact time, initial solution pH, initial Cr (VI) concentration and resin dose on Cr adsorption were studied. Analysis of variance (ANOVA) showed the relative significance of process parameters in removal process. Initial solution pH and resin dose were found to be more significant than contact time and initial Cr (VI) concentration. The second-order regression model was developed to predict the removal efficiency using Design Expert software. The optimal conditions to remove Cr from aqueous solution at constant temperature of 30°C and stirring speed of 250 rpm were found to be contact time 62.5 min, pH 1.96, initial Cr (VI) concentration 145.4 mg/L, and resin dose 8.51 g/L. At these conditions, high removal efficiency (93.26%) was achieved. FTIR and EDX analysis were conducted to interpret the functional groups involved during the Cr-resin interaction. Copyright © 2012 Elsevier B.V. All rights reserved.
Lysack, Mishka
2009-01-01
The Teach-in on Global Warming Solutions is part of a larger socio-environmental movement concerned with combating climate change. Highlighting the history and elements of the teach-in as a model of learning, the article examines the teach-in movement, using a local event at the University of Calgary as an illustration. Conceptual resources from…
Global solutions with infinite energy for the one-dimensional Zakharov system
Directory of Open Access Journals (Sweden)
Hartmut Pecher
2005-04-01
Full Text Available The one-dimensional Zakharov system is shown to have a unique global solution for data without finite energy. The proof uses the ``I-method'' introduced by Colliander, Keel, Staffilani, Takaoka, and Tao in connection with a refined bilinear Strichartz estimate.
Anti-periodic solutions for recurrent neural networks without assuming global Lipschitz conditions
Directory of Open Access Journals (Sweden)
Hong Zhang
2010-04-01
Full Text Available In this paper we study recurrent neural networks with time-varying delays and continuously distributed delays. Without assuming global Lipschitz conditions on the activation functions, we establish the existence and local exponential stability of anti-periodic solutions.
Global Solutions for an -Component System of Activator-Inhibitor Type
Directory of Open Access Journals (Sweden)
S. Abdelmalek
2013-01-01
Full Text Available This paper deals with a reaction-diffusion system with fractional reactions modeling -substances into interaction following activator-inhibitor's scheme. The existence of global solutions is obtained via a judicious Lyapunov functional that generalizes the one introduced by Masuda and Takahashi.
Existence and global exponential stability of periodic solution of CNNs with impulses
Energy Technology Data Exchange (ETDEWEB)
Li Yongkun [Department of Mathematics, Yunnan University, Kunming, Yunnan 650091 (China); Xing Zhiwei [Department of Mathematics, Yunnan University, Kunming, Yunnan 650091 (China)
2007-08-15
Sufficient conditions are obtained for the existence and global exponential stability of a unique periodic solution of cellular neural networks with variable time delays and impulses by using Mawhin's continuation theorem of coincidence degree and by means of a method based on delay differential inequality.
Existence and global exponential stability of periodic solution of CNNs with impulses
International Nuclear Information System (INIS)
Li Yongkun; Xing Zhiwei
2007-01-01
Sufficient conditions are obtained for the existence and global exponential stability of a unique periodic solution of cellular neural networks with variable time delays and impulses by using Mawhin's continuation theorem of coincidence degree and by means of a method based on delay differential inequality
Wada, Y.; Florke, M.; Hanasaki, N.; Eisner, S.; Fischer, G.; Tramberend, S.; Satoh, Y.; van Vliet, M. T. H.; Yillia, P.; Ringler, C.;
2016-01-01
To sustain growing food demand and increasing standard of living, global water use increased by nearly 6 times during the last 100 years, and continues to grow. As water demands get closer and closer to the water availability in many regions, each drop of water becomes increasingly valuable and water must be managed more efficiently and intensively. However, soaring water use worsens water scarcity conditions already prevalent in semi-arid and arid regions, increasing uncertainty for sustainable food production and economic development. Planning for future development and investments requires that we prepare water projections for the future. However, estimations are complicated because the future of the world's waters will be influenced by a combination of environmental, social, economic, and political factors, and there is only limited knowledge and data available about freshwater resources and how they are being used. The Water Futures and Solutions (WFaS) initiative coordinates its work with other ongoing scenario efforts for the sake of establishing a consistent set of new global water scenarios based on the shared socio-economic pathways (SSPs) and the representative concentration pathways (RCPs). The WFaS "fast track" assessment uses three global water models, namely H08, PCR-GLOBWB, and WaterGAP. This study assesses the state of the art for estimating and projecting water use regionally and globally in a consistent manner. It provides an overview of different approaches, the uncertainty, strengths and weaknesses of the various estimation methods, types of management and policy decisions for which the current estimation methods are useful. We also discuss additional information most needed to be able to improve water use estimates and be able to assess a greater range of management options across the water-energy-climate nexus.
The existence of global solution and ''blow up'' phenomenon for the system of multi-dimensional symmetric regularized wave equations
International Nuclear Information System (INIS)
Guo Boling.
1988-08-01
The existence and uniqueness of the global smooth solution for the initial-boundary value problem of the system of multi-dimensions SRWE are proved. The sufficient conditions of ''blowing up'' of the solution are given. (author). 6 refs
A New Global Mascon Solution Tuned for High-Latitude Ice Studies
Luthcke, S. B.; Sabaka, T.; Rowlands, D. D> McCarthy, J. J.; Loomis, B.
2011-01-01
A new global mascon solution has been developed with I-arc-degree spatial and IO-day temporal sampling. The global mas cons are estimated from the reduction of nearly 8 years of GRACE K-band range-rate data. Temporal and anisotropic spatial constraints have been applied for land, ocean and ice regions. The solution construction and tuning is focused towards the Greenland and Antarctic ice sheets (GIS and AIS) as well as the Gulf of Alaska mountain glaciers (GoA). Details of the solution development will be discussed, including the mascon parameter definitions, constraints, and the tuning of the constraint damping factor. Results will be presented, exploring the spatial and temporal variability of the ice sheets and GoA regions. A detailed error analysis will be discussed, including solution dependence on iteration, damping factor, forward modeling, and multitechnique comparisons. We also investigate the fundamental resolution of the solution and the spatial correlation of ice sheet inter-annual change. Finally, we discuss future improvements, including specific constraint application for the rest of the major land ice regions and improvements in solution regularization.
International Nuclear Information System (INIS)
Leite Lopes, J.
1976-01-01
A survey of the fundamental ideas on weak currents such as CVC and PCAC and a presentation of the Cabibbo current and the neutral weak currents according to the Salam-Weinberg model and the Glashow-Iliopoulos-Miami model are given [fr
A New Global Vertical Land Movement Data Set from the TIGA Combined Solution
Hunegnaw, Addisu; Teferle, Felix Norman; Ebuy Abraha, Kibrom; Santamaría-Gómez, Alvaro; Gravelle, Médéric; Wöppelman, Guy; Schöne, Tilo; Deng, Zhiguo; Bingley, Richard; Hansen, Dionne Nicole; Sanchez, Laura; Moore, Michael; Jia, Minghai
2017-04-01
Globally averaged sea level has been estimated from the network of tide gauges installed around the world since the 19th century. These mean sea level (MSL) records provide sea level relative to a nearby tide gauge benchmark (TGBM), which allows for the continuation of the instrumental record in time. Any changes in the benchmark levels, induced by vertical land movements (VLM) affect the MSL records and hence sea level estimates. Over the last two decades sea level has also been observed using satellite altimeters. While the satellite observations are globally more homogeneous providing a picture of sea level not confined to coastlines, they require the VLM-corrected MSL records for the bias calibration of instrumental drifts. Without this calibration altimeter instruments from different missions cannot be combined. GPS has made it possible to obtain highly accurate estimates of VLM in a geocentric reference frame for stations at or close to tide gauges. Under the umbrella of the International GNSS Service (IGS), the Tide Gauge Benchmark Monitoring (TIGA) Working Group (WG) has been established to apply the expertise of the GNSS community to solving issues related to the accuracy and reliability of the vertical component to provide estimates of VLM in a well-defined global reference frame. To achieve this objective, five TIGA Analysis Centers (TACs) contributed re-processed global GPS network solutions to TIGA, employing the latest bias models and processing strategies in accordance with the second re-processing campaign (repro2) of the IGS. These solutions include those of the British Isles continuous GNSS Facility - University of Luxembourg consortium (BLT), the German Research Centre for Geosciences (GFZ) Potsdam, the German Geodetic Research Institute (DGF) at the Technical University of Munich, Geoscience Australia (AUT) and the University of La Rochelle (ULR). In this study we present to the sea level community an evaluation of the VLM estimates from the
Global existence of periodic solutions on a simplified BAM neural network model with delays
International Nuclear Information System (INIS)
Zheng Baodong; Zhang Yazhuo; Zhang Chunrui
2008-01-01
A simplified n-dimensional BAM neural network model with delays is considered. Some results of Hopf bifurcations occurring at the zero equilibrium as the delay increases are exhibited. Global existence of periodic solutions are established using a global Hopf bifurcation result of Wu [Wu J. Symmetric functional-differential equations and neural networks with memory. Trans Am Math Soc 1998;350:4799-838], and a Bendixson criterion for higher dimensional ordinary differential equations due to Li and Muldowney [Li MY, Muldowney J. On Bendixson's criterion. J Differ Equations 1994;106:27-39]. Finally, computer simulations are performed to illustrate the analytical results found
Bourda, Geraldine; Collioud, Arnaud; Charlot, Patrick; Porcas, Richard; Garrington, Simon
2010-01-01
The space astrometry mission Gaia will construct a dense optical QSO-based celestial reference frame. For consistency between optical and radio positions, it will be important to align the Gaia and VLBI frames (International Celestial Reference Frame) with the highest accuracy. In this respect, it is found that only 10% of the ICRF sources are suitable to establish this link (70 sources), either because most of the ICRF sources are not bright enough at optical wavelengths or because they show extended radio emission which precludes reaching the highest astrometric accuracy. In order to improve the situation, we initiated a multi-step VLBI observational project, dedicated to finding additional suitable radio sources for aligning the two frames. The sample consists of about 450 optically-bright radio sources, typically 20 times weaker than the ICRF sources, which have been selected by cross-correlating optical and radio catalogs. The initial observations, aimed at checking whether these sources are detectable with VLBI, and conducted with the European VLBI Network (EVN) in 2007, showed an excellent 90% detection rate. This paper reports on global VLBI observations carried out in March 2008 to image 105 from the 398 previously detected sources. All sources were successfully imaged, revealing compact VLBI structure for about half of them, which is very promising for the future.
An accurate analytical solution of a zero-dimensional greenhouse model for global warming
International Nuclear Information System (INIS)
Foong, S K
2006-01-01
In introducing the complex subject of global warming, books and papers usually use the zero-dimensional greenhouse model. When the ratio of the infrared radiation energy of the Earth's surface that is lost to outer space to the non-reflected average solar radiation energy is small, the model admits an accurate approximate analytical solution-the resulting energy balance equation of the model is a quartic equation that can be solved analytically-and thus provides an alternative solution and instructional strategy. A search through the literature fails to find an analytical solution, suggesting that the solution may be new. In this paper, we review the model, derive the approximation and obtain its solution. The dependence of the temperature of the surface of the Earth and the temperature of the atmosphere on seven parameters is made explicit. A simple and convenient formula for global warming (or cooling) in terms of the percentage change of the parameters is derived. The dependence of the surface temperature on the parameters is illustrated by several representative graphs
International Nuclear Information System (INIS)
Wojcicki, S.
1978-11-01
Lectures are given on weak decays from a phenomenological point of view, emphasizing new results and ideas and the relation of recent results to the new standard theoretical model. The general framework within which the weak decay is viewed and relevant fundamental questions, weak decays of noncharmed hadrons, decays of muons and the tau, and the decays of charmed particles are covered. Limitation is made to the discussion of those topics that either have received recent experimental attention or are relevant to the new physics. (JFP) 178 references
On the theory of weak turbulence for the nonlinear Schrödinger equation
Escobedo, M
2015-01-01
The authors study the Cauchy problem for a kinetic equation arising in the weak turbulence theory for the cubic nonlinear Schrödinger equation. They define suitable concepts of weak and mild solutions and prove local and global well posedness results. Several qualitative properties of the solutions, including long time asymptotics, blow up results and condensation in finite time are obtained. The authors also prove the existence of a family of solutions that exhibit pulsating behavior.
Schildmeijer, Kristina; Nilsson, Lena; Perk, Joep; Arestedt, Kristofer; Nilsson, Gunilla
2013-09-24
The aim was to describe the strengths and weaknesses, from team member perspectives, of working with the Global Trigger Tool (GTT) method of retrospective record review to identify adverse events causing patient harm. A qualitative, descriptive approach with focus group interviews using content analysis. 5 Swedish hospitals in 2011. 5 GTT teams, with 5 physicians and 11 registered nurses. 5 focus group interviews were carried out with the five teams. Interviews were taped and transcribed verbatim. 8 categories emerged relating to the strengths and weaknesses of the GTT method. The categories found were: Usefulness of the GTT, Application of the GTT, Triggers, Preventability of harm, Team composition, Team tasks, Team members' knowledge development and Documentation. Gradually, changes in the methodology were made by the teams, for example, the teams reported how the registered nurses divided up the charts into two sets, each being read respectively. The teams described the method as important and well functioning. Not only the most important, but also the most difficult, was the task of bringing the results back to the clinic. The teams found it easier to discuss findings at their own clinics. The GTT method functions well for identifying adverse events and is strengthened by its adaptability to different specialties. However, small, gradual methodological changes together with continuingly developed expertise and adaption to looking at harm from a patient's perspective may contribute to large differences in assessment over time.
International Nuclear Information System (INIS)
Ogava, S.; Savada, S.; Nakagava, M.
1983-01-01
The problem of the use of weak interaction laws to study models of elementary particles is discussed. The most typical examples of weak interaction is beta-decay of nucleons and muons. Beta-interaction is presented by quark currents in the form of universal interaction of the V-A type. Universality of weak interactions is well confirmed using as examples e- and μ-channels of pion decay. Hypothesis on partial preservation of axial current is applicable to the analysis of processes with pion participation. In the framework of the model with four flavours lepton decays of hadrons are considered. Weak interaction without lepton participation are also considered. Properties of neutral currents are described briefly
International Nuclear Information System (INIS)
Chanda, R.
1981-01-01
The theoretical and experimental evidences to form a basis for Lagrangian Quantum field theory for Weak Interactions are discussed. In this context, gauge invariance aspects of such interactions are showed. (L.C.) [pt
Micheal, MEINDL; Stefan, SCHAER; Urs, HUGENTOBLER; Gerhard, BEUTLER; Astronomical Institute, University of Berne; Astronomical Institute, University of Berne; Astronomical Institute, University of Berne; Astronomical Institute, University of Berne
2004-01-01
Observations at low elevation angles are gathered and used for high accuracy GPS analyses. Introducing tropospheric gradient parameters in the estimation process allows it to take into account of azimuthal variations of tropospheric refraction. This measure significantly improves the repeatability of station coordinates. Most of the mean gradients for stations in the northern and the southern hemisphere show a similar behavior. By combining several years of data from a global solution results...
Global crises, global solutions
National Research Council Canada - National Science Library
Copenhagen Consensus (2004 : Copenhagen, Denmark); Lomborg, Bjørn
2004-01-01
... our response most effectively. Each problem is introduced by a world-renowned expert who deﬁnes the scale of the problem and describes the costs and beneﬁts of a range of policy options to improve the situation. Debate is encouraged through the addition of two sets of 'alternative perspectives' for each proposal, each also written by an internationally recogni...
Existence of global solutions for systems of reaction-diffusion equations on unbounded domains
Directory of Open Access Journals (Sweden)
Salah Badraoui
2002-08-01
Full Text Available We consider, an initial-value problem for the thermal-diffusive combustion system $$displaylines{ u_t=aDelta u-uh(v cr v_t=bDelta u+dDelta v+uh(v, }$$ where $a>0$, $d>0$, $beq 0$, $xin mathbb{R}^n$, $ngeq 1$, with $h(v=v^m$, $m$ is an even nonnegative integer, and the initial data $u_0$, $v_0$ are bounded uniformly continuous and nonnegative. It is known that by a simple comparison if $b=0$, $a=1$, $dleq 1$ and $h(v=v^m$ with $min mathbb{N}^*$, the solutions are uniformly bounded in time. When $d>a=1$, $b=0$, $h(v=v^m$ with $min mathbb{N}^*$, Collet and Xin [2] proved the existence of global classical solutions and showed that the $L^infty $ norm of $v$ can not grow faster than $O(loglog t$ for any space dimension. In our case, no comparison principle seems to apply. Nevertheless using techniques form [2], we essentially prove the existence of global classical solutions if $a
Impact of GPS tracking data of LEO satellites on global GPS solutions
Rothacher, M.; Svehla, D.
Already at present quite a few Low Earth Orbiting (LEO) satellites (SAC-C, CHAMP, JASON-1, GRACE-1 and GRACE-2) are equipped with one or more GPS receivers for precise orbit determination or other applications (atmospheric sounding, gravity field recovery, . . . ). This trend will continue in the near future (e.g., with the GOCE and COSMIC missions) and we will soon have an entire "constellation" of LEO satellites tracked by GPS at our disposal. In this contribution we want to study the impact of LEO GPS measurements (from a single LEO satellite or from a LEO constellation) on global GPS solutions, where GPS satellite orbits and clocks, Earth rotation parameters (ERPs), station coordinates and troposphere zenith delays are determined simultaneously using the data of the global network of the International GPS Service (IGS). In order to assess the impact of the LEO GPS data on global IGS results, we have to perform a combined analysis of the space-borne and the ground-based GPS data. Such a combination may benefit on one hand from the differences between a ground station and a LEO, e.g., (1) the different tracking geometry (coverage of isolated geographical areas by LEOs, rapidly changing geometry, . . . ), (2) that LEOs connect all ground stations within 1-2 hours, (3) that baselines between LEO and ground stations may be longer than station-station baselines, (4) that no tropospheric delays have to be estimated for LEOs, and (5) that LEOs orbit the Earth within the ionosphere and may therefore contribute to global ionosphere models. On the other hand we have to deal with difficult aspects of precise orbit determination for the LEOs: only if we succeed to obtain very accurate dynamic or reduced-dynamic orbits for the LEOs, we will have a chance at all to improve the global GPS results. We present first results concerning the influence of LEO data on GPS orbits, ERPs, site coordinates, and troposphere zenith delays using both, variance-covariance analyses based on
Global interval bifurcation and convex solutions for the Monge-Ampere equations
Directory of Open Access Journals (Sweden)
Wenguo Shen
2018-01-01
Full Text Available In this article, we establish the global bifurcation result from the trivial solutions axis or from infinity for the Monge-Ampere equations with non-differentiable nonlinearity. By applying the above result, we shall determine the interval of $\\gamma$, in which there exist radial solutions for the following Monge-Amp\\`ere equation $$\\displaylines{ \\det(D^2u= \\gamma a(xF(-u,\\quad \\text{in } B,\\cr u(x=0,\\quad \\text{on }\\partial B, }$$ where $D^2u=(\\partial^2u/\\partial x_{i}\\partial x_{j}$ is the Hessian matrix of u, where B is the unit open ball of $\\mathbb{R}^{N}$, $\\gamma$ is a positive parameter. $a\\in C(\\overline{B}, [0,+\\infty$ is a radially symmetric weighted function and $a(r:= a(|x|\
Existence and uniqueness of global solutions for the modified anisotropic 3D Navier−Stokes equations
Bessaih, Hakima
2016-01-27
We study a modified three-dimensional incompressible anisotropic Navier−Stokes equations. The modification consists in the addition of a power term to the nonlinear convective one. This modification appears naturally in porous media when a fluid obeys the Darcy−Forchheimer law instead of the classical Darcy law. We prove global in time existence and uniqueness of solutions without assuming the smallness condition on the initial data. This improves the result obtained for the classical 3D incompressible anisotropic Navier−Stokes equations.
Global stability, periodic solutions, and optimal control in a nonlinear differential delay model
Directory of Open Access Journals (Sweden)
Anatoli F. Ivanov
2010-09-01
Full Text Available A nonlinear differential equation with delay serving as a mathematical model of several applied problems is considered. Sufficient conditions for the global asymptotic stability and for the existence of periodic solutions are given. Two particular applications are treated in detail. The first one is a blood cell production model by Mackey, for which new periodicity criteria are derived. The second application is a modified economic model with delay due to Ramsey. An optimization problem for a maximal consumption is stated and solved for the latter.
The Economic Theory and the Global Crisis, between Theoretical Solutions and the Economic Reality
Directory of Open Access Journals (Sweden)
Nicolae MOROIANU
2011-06-01
Full Text Available This work aims to study the evolution of the global crisis and its impact on various areas worldwide, as well as its impact on certain decisions which have been implemented by the authorized bodies.The general framework of this analysis starts with a short review of the relevant economic movements and trends; it continues with presenting the potential solutions aimed to overcome the dark period which is currently crossed by the contemporary economy.In the same time, the authors aim to highlight the impact of the monetary policies throughput the history on the real economy, until the current period.
Global exponential stability and existence of periodic solutions of CNNs with delays
Dong, Meifang
2002-07-01
In this Letter, we establish general sufficient conditions for global exponential stability and existence of periodic solutions of a class of cellular neural networks (CNNs) with delays. The key to proving the sufficient conditions is the construction of a new Lyapunov functional. An elementary inequality, which may be of independent interest, has been employed in the proof. Checking the sufficient conditions is often reduced to checking some algebraic relations among certain set of parameter. Our sufficient conditions recover the known results in literature as special cases. Finally, we give two examples to illustrate the usage of our main results.
Global Classical Solutions for Partially Dissipative Hyperbolic System of Balance Laws
Xu, Jiang; Kawashima, Shuichi
2014-02-01
The basic existence theory of Kato and Majda enables us to obtain local-in-time classical solutions to generally quasilinear hyperbolic systems in the framework of Sobolev spaces (in x) with higher regularity. However, it remains a challenging open problem whether classical solutions still preserve well-posedness in the case of critical regularity. This paper is concerned with partially dissipative hyperbolic system of balance laws. Under the entropy dissipative assumption, we establish the local well-posedness and blow-up criterion of classical solutions in the framework of Besov spaces with critical regularity with the aid of the standard iteration argument and Friedrichs' regularization method. Then we explore the theory of function spaces and develop an elementary fact that indicates the relation between homogeneous and inhomogeneous Chemin-Lerner spaces (mixed space-time Besov spaces). This fact allows us to capture the dissipation rates generated from the partial dissipative source term and further obtain the global well-posedness and stability by assuming at all times the Shizuta-Kawashima algebraic condition. As a direct application, the corresponding well-posedness and stability of classical solutions to the compressible Euler equations with damping are also obtained.
Klaysom, Chalida; Cath, Tazhi Y; Depuydt, Tom; Vankelecom, Ivo F J
2013-08-21
Osmotically driven membrane processes (ODMP) have gained renewed interest in recent years and they might become a potential solution for the world's most challenging problems of water and energy scarcity. Though the concept of utilizing osmotic pressure difference between high and low salinity streams across semipermeable membranes has been explored for several decades, lack of optimal membranes and draw solutions hindered competition between forward osmosis (FO) and pressure retarded osmosis (PRO) with existing water purification and power generation technologies, respectively. Driven by growing global water scarcity and by energy cost and negative environmental impacts, novel membranes and draw solutions are being developed for ODMPs, mass and heat transfer in osmotic process are becoming better understood, and new applications of ODMPs are emerging. Therefore, OMDPs might become promising green technologies to provide clean water and clean energy from abundantly available renewable resources. This review focuses primarily on new insights into osmotic membrane transport mechanisms and on novel membranes and draw solutions that are currently being developed. Furthermore, the effects of operating conditions on the overall performance of osmotic membranes will be highlighted and future perspectives will be presented.
Blow-Up and Global Existence for a Quasilinear Parabolic System
Directory of Open Access Journals (Sweden)
Chunchen Wu
2014-01-01
Full Text Available The problem of solutions to a class of quasilinear coupling parabolic system was studied. By constructing weak upper-solutions and weak lower-solutions, we obtain the global existence and blow-up of solutions under appropriate conditions.
Anand, Sonia S.; Hawkes, Corinna; Souza, De Russell J.; Mente, Andrew; Dehghan, Mahshid; Nugent, Rachel; Zulyniak, Michael A.; Weis, Tony; Bernstein, Adam M.; Krauss, Ronald M.; Kromhout, Daan; Jenkins, David J.A.; Malik, Vasanti; Martinez-Gonzalez, Miguel A.; Mozaffarian, Dariush; Yusuf, Salim; Willett, Walter C.; Popkin, Barry M.
2015-01-01
Major scholars in the field, on the basis of a 3-day consensus, created an in-depth review of current knowledge on the role of diet in cardiovascular disease (CVD), the changing global food system and global dietary patterns, and potential policy solutions. Evidence from different countries and
Fan, Peilei; Ouyang, Zutao; Basnou, Corina; Pino, Joan; Park, Hogeun; Chen, Jiquan
2017-07-01
Using Barcelona and Shanghai as case studies, we examined the nature-based solutions (NBS) in urban settings-specifically within cities experiencing post-industrialization and globalization. Our specific research questions are: (1) What are the spatiotemporal changes in urban built-up land and green space in Barcelona and Shanghai? (2) What are the relationships between economic development, exemplified by post-industrialization, globalization, and urban green space? Urban land use and green space change were evaluated using data derived from a variety of sources, including satellite images, landscape matrix indicators, and a land conversion matrix. The relationships between economic development, globalization, and environmental quality were analyzed through partial least squares structural equation modeling based on secondary statistical data. Both Barcelona and Shanghai have undergone rapid urbanization, with urban expansion in Barcelona beginning in the 1960s-1970s and in Shanghai in the last decade. While Barcelona's urban green space and green space per capita began declining between the 1950s and 1990s, they increased slightly over the past two decades. Shanghai, however, has consistently and significantly improved urban green space and green space per capita over the past six decades, especially since the economic reform in 1978. Economic development has a direct and significant influence on urban green space for both cities and post-industrialization had served as the main driving force for urban landscape change in Barcelona and Shanghai. Based on secondary statistical and qualitative data from on-site observations and interviews with local experts, we highlighted the institution's role in NBS planning. Furthermore, aspiration to become a global or globalizing city motivated both cities to use NBS planning as a place-making tool to attract global investment, which is reflected in various governing policies and regulations. The cities' effort to achieve a
Directory of Open Access Journals (Sweden)
J. Yan
2016-06-01
Full Text Available This paper presents a global solution to building roof topological reconstruction from LiDAR point clouds. Starting with segmented roof planes from building LiDAR points, a BSP (binary space partitioning algorithm is used to partition the bounding box of the building into volumetric cells, whose geometric features and their topology are simultaneously determined. To resolve the inside/outside labelling problem of cells, a global energy function considering surface visibility and spatial regularization between adjacent cells is constructed and minimized via graph cuts. As a result, the cells are labelled as either inside or outside, where the planar surfaces between the inside and outside form the reconstructed building model. Two LiDAR data sets of Yangjiang (China and Wuhan University (China are used in the study. Experimental results show that the completeness of reconstructed roof planes is 87.5%. Comparing with existing data-driven approaches, the proposed approach is global. Roof faces and edges as well as their topology can be determined at one time via minimization of an energy function. Besides, this approach is robust to partial absence of roof planes and tends to reconstruct roof models with visibility-consistent surfaces.
Directory of Open Access Journals (Sweden)
Mitsuhiro Nakao
2014-01-01
Full Text Available We prove the existence and uniqueness of a global decaying solution to the initial boundary value problem for the quasilinear wave equation with Kelvin-Voigt dissipation and a derivative nonlinearity. To derive the required estimates of the solutions we employ a 'loan' method and use a difference inequality on the energy.
Comparison of the USNO 2016A VLBI Global Solution to ICRF2 and GAIA DR1
Frouard, Julien; Johnson, Megan; Fey, Alan; Makarov, Valeri; Dorland, Bryan
2018-01-01
The Very Long Baseline Interferometry (VLBI) United States Naval Observatory (USNO) 2016A global solution (hereafter, U16A) is part of a work-in-progress effort by the USNO towards the preparation of the third realization of the International Celestial Reference Frame (ICRF3). In this work, we present improved astrometric source positions over the second realization of the ICRF, ICRF2, primarily due to the re-observation of the Very Long Baseline Array Calibrator Survey (VCS) sources (VCS-II, see Gordon et al. (2016)). Our comparison with ICRF2 shows statistically significant offsets of size 0.1 mas between the two solutions. We used the recent Gaia Data Release 1 positions to attempt to understand the nature of these offsets and although we found the GAIA positions are not precise enough to resolve these offsets, they are found to be significantly closer to U16A than ICRF2. In particular, the trend for typically larger errors for Southern sources in VLBI solutions are decreased in U16A. Overall, the VLBI-Gaia offsets are reduced by 21%. The U16A list includes 718 sources not previously included in ICRF2 and 20 of those new sources have statistically significant radio-optical offsets. In two thirds of the cases, these offsets can be explained from PanSTARRS optical images.
Global solutions to the electrodynamic two-body problem on a straight line
Bauer, G.; Deckert, D.-A.; Dürr, D.; Hinrichs, G.
2017-06-01
The classical electrodynamic two-body problem has been a long standing open problem in mathematics. For motion constrained to the straight line, the interaction is similar to that of the two-body problem of classical gravitation. The additional complication is the presence of unbounded state-dependent delays in the Coulomb forces due to the finiteness of the speed of light. This circumstance renders the notion of local solutions meaningless, and therefore, straightforward ODE techniques cannot be applied. Here, we study the time-symmetric case, i.e., the Fokker-Schwarzschild-Tetrode (FST) equations, comprising both advanced and retarded delays. We extend the technique developed in Deckert and Hinrichs (J Differ Equ 260:6900-6929, 2016), where existence of FST solutions was proven on the half line, to ensure global existence—a result that had been obtained by Bauer (Ein Existenzsatz für die Wheeler-Feynman-Elektrodynamik, Herbert Utz Verlag, München, 1997). Due to the novel technique, the presented proof is shorter and more transparent but also relies on the idea to employ asymptotic data to characterize solutions.
Han, Yuzhu; Li, Qingwei
2017-01-01
In this paper we will apply the modified potential well method and variational method to the study of the long time behaviors of solutions to a class of parabolic equation of Kirchhoff type. Global existence and blow up in finite time of solutions will be obtained for arbitrary initial energy. To be a little more precise, we will give a threshold result for the solutions to exist globally or to blow up in finite time when the initial energy is subcritical and critical, respectively. The decay...
Warped AdS6 × S 2 in Type IIB supergravity II: global solutions and five-brane webs
D'Hoker, Eric; Gutperle, Michael; Uhlemann, Christoph F.
2017-05-01
Motivated by the construction of holographic duals to five-dimensional superconformal quantum field theories, we obtain global solutions to Type IIB supergravity invariant under the superalgebra F (4) on a space-time of the form AdS6 × S 2 warped over a two-dimensional Riemann surface Σ. In earlier work, the general local solutions were expressed in terms of two locally holomorphic functions A ± on Σ and global solutions were sketched when Σ is a disk. In the present paper, the physical regularity conditions on the supergravity fields required for global solutions are implemented on A ± for arbitrary Σ. Global solutions exist only when Σ has a non-empty boundary ∂Σ. The differentials ∂ A ± are allowed to have poles only on ∂Σ and each pole corresponds to a semi-infinite ( p, q) five-brane. The construction for the disk is carried out in detail and the conditions for the existence of global solutions are articulated for surfaces with more than one boundary and higher genus.
Global existence of solutions to a tear film model with locally elevated evaporation rates
Gao, Yuan; Ji, Hangjie; Liu, Jian-Guo; Witelski, Thomas P.
2017-07-01
Motivated by a model proposed by Peng et al. (2014) for break-up of tear films on human eyes, we study the dynamics of a generalized thin film model. The governing equations form a fourth-order coupled system of nonlinear parabolic PDEs for the film thickness and salt concentration subject to non-conservative effects representing evaporation. We analytically prove the global existence of solutions to this model with mobility exponents in several different ranges and present numerical simulations that are in agreement with the analytic results. We also numerically capture other interesting dynamics of the model, including finite-time rupture-shock phenomenon due to the instabilities caused by locally elevated evaporation rates, convergence to equilibrium and infinite-time thinning.
The Conversion and Sustainable Use of Alumina Refinery Residues: Global Solution Examples
Fergusson, Lee
This paper introduces current industry best practice for the conversion of alumina refinery residues (or "red mud") from hazardous waste to benign, inert material. The paper will examine four neutralization methods and Basecon Technology, a sustainable conversion process. The paper will consider ways through which this converted material can be combined and processed for sustainable applications in the treatment of hazardous waste streams (such as industrial wastewater and sludges, biosolids, and CCA wastes), contaminated brownfield sites, and mine site wastes. Recent discoveries and applications, such as the successful treatment of high levels of radium in drinking water in the USA, will also be discussed. Examples of global solutions and their technical merits will be assessed.
Go-ICP: A Globally Optimal Solution to 3D ICP Point-Set Registration.
Yang, Jiaolong; Li, Hongdong; Campbell, Dylan; Jia, Yunde
2016-11-01
The Iterative Closest Point (ICP) algorithm is one of the most widely used methods for point-set registration. However, being based on local iterative optimization, ICP is known to be susceptible to local minima. Its performance critically relies on the quality of the initialization and only local optimality is guaranteed. This paper presents the first globally optimal algorithm, named Go-ICP, for Euclidean (rigid) registration of two 3D point-sets under the L 2 error metric defined in ICP. The Go-ICP method is based on a branch-and-bound scheme that searches the entire 3D motion space SE(3). By exploiting the special structure of SE(3) geometry, we derive novel upper and lower bounds for the registration error function. Local ICP is integrated into the BnB scheme, which speeds up the new method while guaranteeing global optimality. We also discuss extensions, addressing the issue of outlier robustness. The evaluation demonstrates that the proposed method is able to produce reliable registration results regardless of the initialization. Go-ICP can be applied in scenarios where an optimal solution is desirable or where a good initialization is not always available.
Global learning for local solutions: Reducing vulnerability of marine-dependent coastal communities
Salim, S. S.; Paytan, A.
2016-12-01
The project `Global learning for local solutions: Reducing vulnerability of marine-dependent coastal communities' (GULLS) falls within the Belmont Forum and G8 Research Councils Initiative on Multilateral Research Funding. Participants include teams from nine countries: Australia, Brazil, India, Madagascar, Mozambique, New Zealand, South Africa, the United Kingdom and the United States of America. The project focuses on five regional `hotspots' of climate and social change, defined as fast-warming marine areas and areas experiencing social tensions as a result of change: south-east Australia, Brazil, India, South Africa, and the Mozambique Channel and adjacent countries of Mozambique and Madagascar. These areas require most urgent attention and serve as valuable case studies for wider applications. The project aims to assist coastal communities and other stakeholders dependent on marine resources to adapt to climate change and variability through an integrated and trans-disciplinary approach. Combining best available global knowledge with local knowledge and conditions, it is exploring adaptation options and approaches to strengthen resilience at local and community levels, with a focus on options for reconciling the needs for food security with long-term sustainability and conservation. The project will also contribute to capacity development and empowering fishing communities and other fisheries-dependent stakeholders.A standardized vulnerability assessment framework is being developed that will be used to integrate results from natural, social and economic studies in order to identify needs and options for strengthening management and existing policies. Structured comparisons between the hot-spots will assist global efforts for adaptation and strengthening resilience in marine and coastal social-ecological systems.
Directory of Open Access Journals (Sweden)
Hubertus Hertzberg
2013-08-01
Full Text Available Infections with parasitic helminths (nematodes and trematodes represent a significant economic and welfare burden to the global ruminant livestock industry. The increasing prevalence of anthelmintic resistance means that current control programmes are costly and unsustainable in the long term. Recent changes in the epidemiology, seasonality and geographic distribution of helminth infections have been attributed to climate change. However, other changes in environment (e.g., land use and in livestock farming, such as intensification and altered management practices, will also have an impact on helminth infections. Sustainable control of helminth infections in a changing world requires detailed knowledge of these interactions. In particular, there is a need to devise new, sustainable strategies for the effective control of ruminant helminthoses in the face of global change. In this paper, we consider the impact of helminth infections in grazing ruminants, taking a European perspective, and identify scientific and applied priorities to mitigate these impacts. These include the development and deployment of efficient, high-throughput diagnostic tests to support targeted intervention, modelling of geographic and seasonal trends in infection, more thorough economic data and analysis of the impact of helminth infections and greater translation and involvement of end-users in devising and disseminating best practices. Complex changes in helminth epidemiology will require innovative solutions. By developing and using new technologies and models, the use of anthelmintics can be optimised to limit the development and spread of drug resistance and to reduce the overall economic impact of helminth infections. This will be essential to the continued productivity and profitability of livestock farming in Europe and its contribution to regional and global food security.
Wani, Naveel; Maqbool, Bari; Iqbal, Naseer; Misra, Ranjeev
2016-07-01
X-ray binaries and AGNs are powered by accretion discs around compact objects, where the x-rays are emitted from the inner regions and uv emission arise from the relatively cooler outer parts. There has been an increasing evidence that the variability of the x-rays in different timescales is caused by stochastic fluctuations in the accretion disc at different radii. These fluctuations although arise in the outer parts of the disc but propagate inwards to give rise to x-ray variability and hence provides a natural connection between the x-ray and uv variability. There are analytical expressions to qualitatively understand the effect of these stochastic variabilities, but quantitative predictions are only possible by a detailed hydrodynamical study of the global time dependent solution of standard accretion disc. We have developed numerical efficient code (to incorporate all these effects), which considers gas pressure dominated solutions and stochastic fluctuations with the inclusion of boundary effect of the last stable orbit.
Chapter 6. Scaling Up Solutions to State, National and Global Levels
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Daniel Kammen
2016-12-01
Full Text Available Scaling-up solutions require learning and adapting lessons between locations and at different scales. To accomplish this, common metrics are vital to building a shared language. For California, this has meant careful financial, cradle-to-grave life-cycle assessment methods leading to carbon accounting in many avenues of government (via the Low Carbon Fuel Standard or the Cap and Trade program. These methods themselves interact, such as the use of carbon accounting for the resources needed to manage water and other key resources; the use of criteria air pollution monitoring to identify environmental injustices; and the use of carbon market revenues to address these inequalities, through investment in best available abatement technologies (BACT and in job creation in disadvantaged communities anticipated in the emerging clean energy sector. Creating interdisciplinary partnerships across the UC Campuses and the National Laboratories to innovate science and technology is critical to scalable carbon neutrality solutions. As an example, we can build coordinated research and development programs across UC and California, with strong partnerships with the Federal government to coordinate and “multiply” resources that accelerate development and deployment. These partnerships should be strongly goal-focused, i.e., they are created to solve specific, large problems, to enable quantitatively measurable outcomes within energy generation, efficiency and CO2 abatement categories. Intersectoral partnerships should be fostered across campuses, laboratories, with state, federal and multi-lateral organizations funding to develop technologies and deploy solutions at scale. Integrated partnerships with industry are required to influence markets, deploy solutions, and create new industries and jobs. Beyond California, we need to establish consortia with industry and foundations to deploy solutions at the regional, state, national, and international scale to
Ferguson, J; Livan, M; Nordberg, M; Salmia, T; Vuola, O
2003-01-01
In today's global organisations and networks, a critical factor for effective innovation and project execution is appropriate competence and skills management. The challenges include selection of strategic competences, competence development, and leveraging the competences and skills to drive innovation and collaboration for shared goals. This paper presents a new industrial web-enabled competence management and networking solution and its implementation and piloting in a complex big-science environment of globally distributed competences.
International Nuclear Information System (INIS)
Song Qiankun; Cao Jinde
2005-01-01
Both exponential stability and periodic solutions are considered for a class of bi-directional associative memory (BAM) neural networks with delays and reaction-diffusion terms by constructing suitable Lyapunov functional and some analysis techniques. The general sufficient conditions are given ensuring the global exponential stability and existence of periodic solutions of BAM neural networks with delays and reaction-diffusion terms. These presented conditions are in terms of system parameters and have important leading significance in the design and applications of globally exponentially stable and periodic oscillatory neural circuits for BAM with delays and reaction-diffusion terms
Czech Academy of Sciences Publication Activity Database
Fojtíková, Lucia; Zahradník, J.
2014-01-01
Roč. 85, č. 6 (2014), s. 1265-1274 ISSN 0895-0695 R&D Projects: GA ČR GAP210/12/2336 Institutional support: RVO:67985891 Keywords : weak events * sparse networks * focal mechanism * waveform inversion Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.156, year: 2014 http://srl.geoscienceworld.org/content/85/6/1265.full
Alonso, Wladimir Jimenez; McCormick, Benjamin Joseph James; Miller, Mark A; Schuck-Paim, Cynthia; Asrar, Ghassem R
2015-09-24
Efforts in global heath need to deal not only with current challenges, but also to anticipate new scenarios, which sometimes unfold at lightning speed. Predictive modeling is frequently used to assist planning, but outcomes depend heavily on a subset of critical assumptions, which are mostly hampered by our limited knowledge about the many factors, mechanisms and relationships that determine the dynamics of disease systems, by a lack of data to parameterize and validate models, and by uncertainties about future scenarios. We propose a shift from a focus on the prediction of individual disease patterns to the identification and mitigation of broader fragilities in public health systems. Modeling capabilities should be used to perform "stress tests" on how interrelated fragilities respond when faced with a range of possible or plausible threats of different nature and intensity. This system should be able to reveal crosscutting solutions with the potential to address not only one threat, but multiple areas of vulnerability to future health risks. Actionable knowledge not based on a narrow subset of threats and conditions can better guide policy, build societal resilience and ensure effective prevention in an uncertain world.
On global solutions of the random Hamilton-Jacobi equations and the KPZ problem
Bakhtin, Yuri; Khanin, Konstantin
2018-04-01
In this paper, we discuss possible qualitative approaches to the problem of KPZ universality. Throughout the paper, our point of view is based on the geometrical and dynamical properties of minimisers and shocks forming interlacing tree-like structures. We believe that the KPZ universality can be explained in terms of statistics of these structures evolving in time. The paper is focussed on the setting of the random Hamilton-Jacobi equations. We formulate several conjectures concerning global solutions and discuss how their properties are connected to the KPZ scalings in dimension 1 + 1. In the case of general viscous Hamilton-Jacobi equations with non-quadratic Hamiltonians, we define generalised directed polymers. We expect that their behaviour is similar to the behaviour of classical directed polymers, and present arguments in favour of this conjecture. We also define a new renormalisation transformation defined in purely geometrical terms and discuss conjectural properties of the corresponding fixed points. Most of our conjectures are widely open, and supported by only partial rigorous results for particular models.
Numerical test of weak turbulence theory
Payne, G. L.; Nicholson, D. R.; Shen, Mei-Mei
1989-01-01
The analytic theory of weak Langmuir turbulence is well known, but very little has previously been done to compare its predictions with numerical solutions of the basic dynamical evolution equations. In this paper, numerical solutions of the statistical weak turbulence theory are compared with numerical solutions of the Zakharov model of Langmuir turbulence, and good agreement in certain regimes of very weak field strength is found.
Directory of Open Access Journals (Sweden)
Chaolang Hu
2012-01-01
Full Text Available In order to increase productivity, it is important to study the performance of a hydraulically fractured well producing at constant wellbore pressure. This paper constructs a new productivity formula, which is obtained by solving a weakly singular integral equation of the first kind, for an infinite-conductivity hydraulically fractured well producing at constant pressure. And the two key components of this paper are a weakly singular integral equation of the first kind and a steady-state productivity formula. A new midrectangle algorithm and a Galerkin method are presented in order to solve the weakly singular integral equation. The numerical results of these two methods are in accordance with each other. And then the solutions of the weakly singular integral equation are utilized for the productivity formula of hydraulic fractured wells producing at constant pressure, which provide fast analytical tools to evaluate production performance of infinite-conductivity fractured wells. The paper also shows equipotential threads, which are generated from the numerical results, with different fluid potential values. These threads can be approximately taken as a family of ellipses whose focuses are the two endpoints of the fracture, which is in accordance with the regular assumption in Kuchuk and Brigham, 1979.
Evaluation of Proposed Solutions to Global Warming, Air Pollution, and Energy Security
Jacobson, M. Z.
2008-12-01
This study reviews and ranks major proposed solutions to global warming, air pollution mortality, and energy security while considering other impacts of the proposed solutions, such as on water supply, land use, wildlife, resource availability, thermal pollution, water chemical pollution, nuclear proliferation, and undernutrition. Nine electric power sources and two liquid fuel options are considered. The electricity sources include solar-photovoltaics (PV), concentrated solar power (CSP), wind, geothermal, hydroelectric, wave, tidal, nuclear, and coal with carbon capture and storage (CCS) technology. The liquid fuel options include corn-E85 and cellulosic E85. To place the electric and liquid fuel sources on an equal footing, we examine their comparative abilities to address the problems mentioned by powering new-technology vehicles, including battery-electric vehicles (BEVs), hydrogen fuel cell vehicles (HFCVs), and flex-fuel vehicles run on E85. Twelve combinations of energy source-vehicle type are considered. Upon ranking and weighting each combination with respect to each of 11 impact categories, four clear divisions of ranking, or tiers, emerge. Tier 1 (highest-ranked) includes wind-BEVs and wind-HFCVs. Tier 2 includes CSP-BEVs, geothermal-BEVs, PV-BEVs, tidal-BEVs, and wave-BEVs. Tier 3 includes hydro-BEVs, nuclear-BEVs, and CCS-BEVs. Tier 4 includes corn- and cellulosic-E85. Wind-BEVs ranked first in six out of 11 categories, including the two most important, mortality and climate damage reduction. Although HFCVs are less efficient than BEVs, wind- HFCVs ranked second among all combinations. Tier 2 options provide significant benefits and are recommended. Tier 3 options are less desirable. However, hydroelectricity, which was ranked ahead of coal- CCS and nuclear with respect to climate and health, is an excellent load balancer, thus strongly recommended. The Tier-4 combinations (cellulosic- and corn-E85) were ranked lowest overall and with respect to
Directory of Open Access Journals (Sweden)
2006-01-01
Full Text Available We derive necessary and sufficient conditions for global-in-time existence of solutions of ordinary differential, stochastic differential, and parabolic equations. The conditions are formulated in terms of complete Riemannian metrics on extended phase spaces (conditions with two-sided estimates or in terms of derivatives of proper functions on extended phase spaces (conditions with one-sided estimates.
Directory of Open Access Journals (Sweden)
Hong Zhang
2014-01-01
Full Text Available This paper is concerned with a nonautonomous fishing model with a time-varying delay. Under proper conditions, we employ a novel argument to establish a criterion on the global exponential stability of positive almost periodic solutions of the model with almost periodic coefficients and delays. Moreover, an example and its numerical simulation are given to illustrate the main results.
Jun, Li; Huicheng, Yin
2018-05-01
The paper is devoted to investigating long time behavior of smooth small data solutions to 3-D quasilinear wave equations outside of compact convex obstacles with Neumann boundary conditions. Concretely speaking, when the surface of a 3-D compact convex obstacle is smooth and the quasilinear wave equation fulfills the null condition, we prove that the smooth small data solution exists globally provided that the Neumann boundary condition on the exterior domain is given. One of the main ingredients in the current paper is the establishment of local energy decay estimates of the solution itself. As an application of the main result, the global stability to 3-D static compressible Chaplygin gases in exterior domain is shown under the initial irrotational perturbation with small amplitude.
Energy Technology Data Exchange (ETDEWEB)
Sanz, S.
2009-07-01
Radioactively contaminated metallic materials: the search for a global solution. Tarragona hosted the first International Conference on Control and Management of Inadvertent Radioactive Material in Metal Scrap, which was sponsored by the IAEA and organised by various Spanish entities, among them the CSN. The meeting served for the exchange of ideas and precautionary measures, a field in which Spain already has a long and recognised experience, and focussed on the voluntary Protocol, endorsed by the majority of the Spanish steelyards. (Author)
Telehealth solutions to enable global collaboration in rheumatic heart disease screening.
Lopes, Eduardo Lv; Beaton, Andrea Z; Nascimento, Bruno R; Tompsett, Alison; Dos Santos, Julia Pa; Perlman, Lindsay; Diamantino, Adriana C; Oliveira, Kaciane Kb; Oliveira, Cassio M; Nunes, Maria do Carmo P; Bonisson, Leonardo; Ribeiro, Antônio Lp; Sable, Craig
2018-02-01
Background The global burden of rheumatic heart disease is nearly 33 million people. Telemedicine, using cloud-server technology, provides an ideal solution for sharing images performed by non-physicians with cardiologists who are experts in rheumatic heart disease. Objective We describe our experience in using telemedicine to support a large rheumatic heart disease outreach screening programme in the Brazilian state of Minas Gerais. Methods The Programa de Rastreamento da Valvopatia Reumática (PROVAR) is a prospective cross-sectional study aimed at gathering epidemiological data on the burden of rheumatic heart disease in Minas Gerais and testing of a non-expert, telemedicine-supported model of outreach rheumatic heart disease screening. The primary goal is to enable expert support of remote rheumatic heart disease outreach through cloud-based sharing of echocardiographic images between Minas Gerais and Washington. Secondary goals include (a) developing and sharing online training modules for non-physicians in echocardiography performance and interpretation and (b) utilising a secure web-based system to share clinical and research data. Results PROVAR included 4615 studies that were performed by non-experts at 21 schools and shared via cloud-telemedicine technology. Latent rheumatic heart disease was found in 251 subjects (4.2% of subjects: 3.7% borderline and 0.5% definite disease). Of the studies, 50% were preformed on full functional echocardiography machines and transmitted via Digital Imaging and Communications in Medicine (DICOM) and 50% were performed on handheld echocardiography machines and transferred via a secure Dropbox connection. The average time between study performance date and interpretation was 10 days. There was 100% success in initial image transfer. Less than 1% of studies performed by non-experts could not be interpreted. Discussion A sustainable, low-cost telehealth model, using task-shifting with non-medical personal in low and middle
Book Review: Cyber Security and Global Information Assurance: Threat Analysis and Response Solutions
Directory of Open Access Journals (Sweden)
Gary Kessler
2009-09-01
Full Text Available Knapp, K.J. (Ed. (2009. Cyber Security and Global Information Assurance: Threat Analysis and Response Solutions. Hershey, NY: Information Science Reference. 434 + xxii pages, ISBN: 978-1-60566-326-5, US$195.Reviewed by Gary C. Kessler (gck@garykessler.netI freely admit that this book was sent to me by the publisher for the expressed purpose of my writing a review and that I know several of the chapter authors. With that disclosure out of the way, let me say that the book is well worth the review (and I get to keep my review copy.The preface to the book cites the 2003 publication of The National Strategy to Secure Cyberspace by the White House, and the acknowledgement by the U.S. government that our economy and national security were fully dependent upon computers, networks, and the telecommunications infrastructure. This mayhave come as news to the general population but it was a long overdue public statement to those of us in the industry. The FBI's InfraGard program and the formation of the National Infrastructure Protection Center (NIPC pre-dated this report by at least a half-dozen years, so the report was hardly earthshattering. And the fact that the bulk of the telecom infrastructure is owned by the private sector is a less advertized fact. Nonetheless, reminding the community of these facts is always a Good Thing and provides the raison dâ€™Ãªtre of this book.(see PDF for full review
Helfenstein, Julian; Jegminat, Jannes; McLaren, Timothy I.; Frossard, Emmanuel
2018-01-01
The exchange rate of inorganic phosphorus (P) between the soil solution and solid phase, also known as soil solution P turnover, is essential for describing the kinetics of bioavailable P. While soil solution P turnover (Km) can be determined by tracing radioisotopes in a soil-solution system, few studies have done so. We believe that this is due to a lack of understanding on how to derive Km from isotopic exchange kinetic (IEK) experiments, a common form of radioisotope dilution study. Here, we provide a derivation of calculating Km using parameters obtained from IEK experiments. We then calculated Km for 217 soils from published IEK experiments in terrestrial ecosystems, and also that of 18 long-term P fertilizer field experiments. Analysis of the global compilation data set revealed a negative relationship between concentrations of soil solution P and Km. Furthermore, Km buffered isotopically exchangeable P in soils with low concentrations of soil solution P. This finding was supported by an analysis of long-term P fertilizer field experiments, which revealed a negative relationship between Km and phosphate-buffering capacity. Our study highlights the importance of calculating Km for understanding the kinetics of P between the soil solid and solution phases where it is bioavailable. We argue that our derivation can also be used to calculate soil solution turnover of other environmentally relevant and strongly sorbing elements that can be traced with radioisotopes, such as zinc, cadmium, nickel, arsenic, and uranium.
Weakly Supervised Deep Detection Networks
Bilen, Hakan; Vedaldi, Andrea
2015-01-01
Weakly supervised learning of object detection is an important problem in image understanding that still does not have a satisfactory solution. In this paper, we address this problem by exploiting the power of deep convolutional neural networks pre-trained on large-scale image-level classification tasks. We propose a weakly supervised deep detection architecture that modifies one such network to operate at the level of image regions, performing simultaneously region selection and classificati...
Li, Hongfei; Jiang, Haijun; Hu, Cheng
2016-03-01
In this paper, we investigate a class of memristor-based BAM neural networks with time-varying delays. Under the framework of Filippov solutions, boundedness and ultimate boundedness of solutions of memristor-based BAM neural networks are guaranteed by Chain rule and inequalities technique. Moreover, a new method involving Yoshizawa-like theorem is favorably employed to acquire the existence of periodic solution. By applying the theory of set-valued maps and functional differential inclusions, an available Lyapunov functional and some new testable algebraic criteria are derived for ensuring the uniqueness and global exponential stability of periodic solution of memristor-based BAM neural networks. The obtained results expand and complement some previous work on memristor-based BAM neural networks. Finally, a numerical example is provided to show the applicability and effectiveness of our theoretical results. Copyright © 2015 Elsevier Ltd. All rights reserved.
Yee, H. C.; Sweby, P. K.
1995-01-01
The global asymptotic nonlinear behavior of 1 1 explicit and implicit time discretizations for four 2 x 2 systems of first-order autonomous nonlinear ordinary differential equations (ODES) is analyzed. The objectives are to gain a basic understanding of the difference in the dynamics of numerics between the scalars and systems of nonlinear autonomous ODEs and to set a baseline global asymptotic solution behavior of these schemes for practical computations in computational fluid dynamics. We show how 'numerical' basins of attraction can complement the bifurcation diagrams in gaining more detailed global asymptotic behavior of time discretizations for nonlinear differential equations (DEs). We show how in the presence of spurious asymptotes the basins of the true stable steady states can be segmented by the basins of the spurious stable and unstable asymptotes. One major consequence of this phenomenon which is not commonly known is that this spurious behavior can result in a dramatic distortion and, in most cases, a dramatic shrinkage and segmentation of the basin of attraction of the true solution for finite time steps. Such distortion, shrinkage and segmentation of the numerical basins of attraction will occur regardless of the stability of the spurious asymptotes, and will occur for unconditionally stable implicit linear multistep methods. In other words, for the same (common) steady-state solution the associated basin of attraction of the DE might be very different from the discretized counterparts and the numerical basin of attraction can be very different from numerical method to numerical method. The results can be used as an explanation for possible causes of error, and slow convergence and nonconvergence of steady-state numerical solutions when using the time-dependent approach for nonlinear hyperbolic or parabolic PDES.
International Nuclear Information System (INIS)
Tang, X H; Zou, Xingfu
2009-01-01
By employing Schauder's fixed point theorem and a non-Liapunov method (matrix theory, inequality analysis), we obtain some new criteria that ensure existence and global exponential stability of a periodic solution to a class of functional differential equations. Applying these criteria to a cellular neural network with time delays (delayed cellular neural network, DCNN) under a periodic environment leads to some new results that improve and generalize many existing ones we know on this topic. These results are of great significance in designs and applications of globally stable periodic DCNNs
Qin, Yuming
2016-01-01
This book presents recent findings on the global existence, the uniqueness and the large-time behavior of global solutions of thermo(vis)coelastic systems and related models arising in physics, mechanics and materials science such as thermoviscoelastic systems, thermoelastic systems of types II and III, as well as Timoshenko-type systems with past history. Part of the book is based on the research conducted by the authors and their collaborators in recent years. The book will benefit interested beginners in the field and experts alike.
Wijaya, A. S.
2014-03-01
Climate change becomes one of the most significant challenges faced by most environmentalist all over the world. Every country either developed or developing one has the same need in climate change impact mitigation and adaptation. However, developed countries are believed to have better ability rather than developing countries in particular to climate change adaptation impact. It is described by several indications pointed out by several practitioners. The methods compare findings in both developing and developed countries. It is analyzing two salient data justified by rational arguments and emphasizing with some justifications then finally summarizing with solutions and recommendations.
Directory of Open Access Journals (Sweden)
Imed Bachar
2014-01-01
Full Text Available We are interested in the following fractional boundary value problem: Dαu(t+atuσ=0, t∈(0,∞, limt→0t2-αu(t=0, limt→∞t1-αu(t=0, where 1<α<2, σ∈(-1,1, Dα is the standard Riemann-Liouville fractional derivative, and a is a nonnegative continuous function on (0,∞ satisfying some appropriate assumptions related to Karamata regular variation theory. Using the Schauder fixed point theorem, we prove the existence and the uniqueness of a positive solution. We also give a global behavior of such solution.
Global stability and existence of periodic solutions of discrete delayed cellular neural networks
International Nuclear Information System (INIS)
Li Yongkun
2004-01-01
We use the continuation theorem of coincidence degree theory and Lyapunov functions to study the existence and stability of periodic solutions for the discrete cellular neural networks (CNNs) with delays xi(n+1)=xi(n)e-bi(n)h+θi(h)-bar j=1maij(n)fj(xj(n))+θi(h)-bar j=1mbij(n)fj(xj(n- τij(n)))+θi(h)Ii(n),i=1,2,...,m. We obtain some sufficient conditions to ensure that for the networks there exists a unique periodic solution, and all its solutions converge to such a periodic solution
International Nuclear Information System (INIS)
Tutuianu, O.; Fulger, E.D.; Vieru, A.; Feher, M.
1996-01-01
This paper deals with the present state of RENEL (Romanian Electricity Authority) - controlled thermal power plants from the point of view of technical aspects, utilized fuels and pollutant emissions. National and international regulations are also analyzed as well as their implications concerning the management of pollutant atmospheric emissions of the plants of RENEL. Starting from these premises the paper points out the advantage of global approach of pollution problems and offers solutions already implemented by RENEL. This global approach will result in an optimization of costs implied in pollutant emission limitations as the most efficient solution were found and applied. Having in view this treatment of the pollution problems, RENEL has submitted to the Ministry of the Industries and to the Ministry of Waters, Forests and Environmental Protection a 'Convention on the limitation of CO 2 , SO 2 and NO x emissions produced in the thermal power plants of RENEL'. (author)
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Rong Yuan
2010-02-01
Full Text Available This article studies the existence of homoclinic solutions for the second-order non-autonomous Hamiltonian system $$ ddot q-L(tq+W_{q}(t,q=0, $$ where $Lin C(mathbb{R},mathbb{R}^{n^2}$ is a symmetric and positive definite matrix for all $tin mathbb{R}$. The function $Win C^{1}(mathbb{R}imesmathbb{R}^{n},mathbb{R}$ is not assumed to satisfy the global Ambrosetti-Rabinowitz condition. Assuming reasonable conditions on $L$ and $W$, we prove the existence of at least one nontrivial homoclinic solution, and for $W(t,q$ even in $q$, we prove the existence of infinitely many homoclinic solutions.
Fraile, J. M.; Lopezgomez, J.; Delis, J. C.
1995-11-01
In this work we analyze the structure of the set of positive solutions of a class of semilinear boundary value problems. It is shown that the global continuum of positive solutions emanating from the trivial equilibrium at the principal eigenvalue of the linearization is constituted by a regular curve if the slope of the kinetic at the trivial solution is large enough and Ω is convex. The same result holds if the support region of the species is a bounded simply connected domain of R2 close to a convex domain, in a sense to be precised later. To prove these results we have to find out the exact width of the boundary layer of a singular perturbation problem. The results about the singular perturbation problem are new and of great interest by themselves.
Competition among networks highlights the power of the weak
Iranzo, Jaime; Buldú, Javier M.; Aguirre, Jacobo
2016-11-01
The unpreventable connections between real networked systems have recently called for an examination of percolation, diffusion or synchronization phenomena in multilayer networks. Here we use network science and game theory to explore interactions in networks-of-networks and model these as a game for gaining importance. We propose a viewpoint where networks choose the connection strategies, in contrast with classical approaches where nodes are the active players. Specifically, we investigate how creating paths between networks leads to different Nash equilibria that determine their structural and dynamical properties. In a wide variety of cases, selecting adequate connections leads to a cooperative solution that allows weak networks to overcome the strongest opponent. Counterintuitively, each weak network can induce a global transition to such cooperative configuration regardless of the actions of the strongest network. This power of the weak reveals a critical dominance of the underdogs in the fate of networks-of-networks.
Global existence of solutions of integral equations with delay: progressive contractions
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Theodore Burton
2017-06-01
with initial function $\\omega$ with $\\omega (0 =L(0$ defined by $ t\\leq 0 \\implies x(t =\\omega (t$ is studied on an interval $[0,E]$ with $r(t \\geq \\alpha >0$. The interval $[0,E]$ is divided into parts by $0=T_00$ on $[0,\\infty$ we obtain a unique solution on that interval as follows. As we let $E= 1,2,\\dots$ we obtain a sequence of solutions on $[0,n]$ which we extend to $[0,\\infty$ by a horizontal line, thereby obtaining functions converging uniformly on compact sets to a solution on $[0,\\infty$. Lemma 2.1 extends progressive contractions to delay equations
Big Data challenges and solutions in building the Global Earth Observation System of Systems (GEOSS)
Mazzetti, Paolo; Nativi, Stefano; Santoro, Mattia; Boldrini, Enrico
2014-05-01
The Group on Earth Observation (GEO) is a voluntary partnership of governments and international organizations launched in response to calls for action by the 2002 World Summit on Sustainable Development and by the G8 (Group of Eight) leading industrialized countries. These high-level meetings recognized that international collaboration is essential for exploiting the growing potential of Earth observations to support decision making in an increasingly complex and environmentally stressed world. To this aim is constructing the Global Earth Observation System of Systems (GEOSS) on the basis of a 10-Year Implementation Plan for the period 2005 to 2015 when it will become operational. As a large-scale integrated system handling large datasets as those provided by Earth Observation, GEOSS needs to face several challenges related to big data handling and big data infrastructures management. Referring to the traditional multiple Vs characteristics of Big Data (volume, variety, velocity, veracity and visualization) it is evident how most of them can be found in data handled by GEOSS. In particular, concerning Volume, Earth Observation already generates a large amount of data which can be estimated in the range of Petabytes (1015 bytes), with Exabytes (1018) already targeted. Moreover, the challenge is related not only to the data size, but also to the large amount of datasets (not necessarily having a big size) that systems need to manage. Variety is the other main challenge since datasets coming from different sensors, processed for different use-cases are published with highly heterogeneous metadata and data models, through different service interfaces. Innovative multidisciplinary applications need to access and use those datasets in a harmonized way. Moreover Earth Observation data are growing in size and variety at an exceptionally fast rate and new technologies and applications, including crowdsourcing, will even increase data volume and variety in the next future
Non linear Euler-Poisson system. Part 1: global existence of low entropy solutions
International Nuclear Information System (INIS)
Cordier, S.
1995-05-01
In this work a 1-D model of electrons and ions plasma is considered. Electrons are supposed to be in Maxwell-Boltzmann thermodynamic equilibrium while ions are described with an isothermal flow model of charged particles submitted to a self-consistent electric field. A collision term between neutral particles and ions simulates the presence of neutral particles. This work demonstrates the existence of low entropy solutions for this simple model with arbitrary initial conditions. Most of the paper is devoted to the demonstration of this theorem and follows the successive steps: construction of a numerical scheme, recall of the classical properties of Riemann problem solutions using Glimm method, uniform estimations for the whole variation norm, and finally, convergence of the constructed solutions towards a low entropy solution for the non-linear Euler/Poisson system. Domains of application for this type of model are listed in the conclusion. (J.S.). 18 refs
Global solutions to random 3D vorticity equations for small initial data
Barbu, Viorel; Röckner, Michael
2017-11-01
One proves the existence and uniqueness in (Lp (R3)) 3, 3/2 4p - 6)3 with respect to the time variable. Furthermore, we obtain the pathwise continuous dependence of solutions with respect to the initial data. In particular, one gets a locally unique solution of 3D stochastic Navier-Stokes equation in vorticity form up to some explosion stopping time τ adapted to the Brownian motion.
Shibuya, Takazo; Komiya, Tsuyoshi; Takai, Ken; Maruyama, Shigenori; Russell, Michael J.
2017-12-01
It was previously revealed that the total CO2 concentration in seawater decreased during the Late Archean. In this paper, to assess the secular change of total CO2 concentration in seawater, we focused on the Paleoproterozoic era when the Earth experienced its first recorded global glaciation. The 2.4 Ga Ongeluk Formation outcrops in the Kaapvaal Craton, South Africa. The formation consists mainly of submarine volcanic rocks that have erupted during the global glaciation. The undeformed lavas are mostly carbonate-free but contain rare disseminated calcites. The carbon isotope ratio of the disseminated calcite (δ13Ccc vs. VPDB) ranges from - 31.9 to - 13.2 ‰. The relatively low δ13Ccc values clearly indicate that the carbonation was partially contributed by 13C-depleted CO2 derived from decomposition of organic matter beneath the seafloor. The absence of δ13Ccc higher than - 13.2‰ is consistent with the exceptionally 13C-depleted CO2 in the Ongeluk seawater during glaciation. The results suggest that carbonation occurred during subseafloor hydrothermal circulation just after the eruption of the lavas. Previously, it was reported that the carbonate content in the uppermost subseafloor crust decreased from 3.2 to 2.6 Ga, indicating a decrease in total CO2 concentration in seawater during that time. However, the average CO2 (as carbonate) content in the Ongeluk lavas (extremely low CO2 concentration in seawater during the global glaciation. Considering that the carbonate content of the subseafloor crusts also shows a good correlation with independently estimated atmospheric pCO2 levels through the Earth history, it seem highly likely that the low carbonate content in the Ongeluk lavas reflects the low atmospheric pCO2 at that time. We conclude that the continuous decrease in CO2 concentration of seawater/atm. from 3.2 Ga was one of the contributing factors to the Paleoproterozoic global glaciation.
Directory of Open Access Journals (Sweden)
Tulio Rosembuj
2006-12-01
Full Text Available There is no singular globalization, nor is the result of an individual agent. We could start by saying that global action has different angles and subjects who perform it are different, as well as its objectives. The global is an invisible invasion of materials and immediate effects.
Tulio Rosembuj
2006-01-01
There is no singular globalization, nor is the result of an individual agent. We could start by saying that global action has different angles and subjects who perform it are different, as well as its objectives. The global is an invisible invasion of materials and immediate effects.
Gray, Adrian J; Shorter, Kathleen; Cummins, Cloe; Murphy, Aron; Waldron, Mark
2018-03-27
Quantifying the training and competition loads of players in contact team sports can be performed in a variety of ways, including kinematic, perceptual, heart rate or biochemical monitoring methods. Whilst these approaches provide data relevant for team sports practitioners and athletes, their application to a contact team sport setting can sometimes be challenging or illogical. Furthermore, these methods can generate large fragmented datasets, do not provide a single global measure of training load and cannot adequately quantify all key elements of performance in contact team sports. A previous attempt to address these limitations via the estimation of metabolic energy demand (global energy measurement) has been criticised for its inability to fully quantify the energetic costs of team sports, particularly during collisions. This is despite the seemingly unintentional misapplication of the model's principles to settings outside of its intended use. There are other hindrances to the application of such models, which are discussed herein, such as the data-handling procedures of Global Position System manufacturers and the unrealistic expectations of end users. Nevertheless, we propose an alternative energetic approach, based on Global Positioning System-derived data, to improve the assessment of mechanical load in contact team sports. We present a framework for the estimation of mechanical work performed during locomotor and contact events with the capacity to globally quantify the work done during training and matches.
Directory of Open Access Journals (Sweden)
Maria de Hoyos Guajardo, Ph.D. Candidate, M.Sc., B.Eng.
2004-11-01
Full Text Available The theory that is presented below aims to conceptualise how a group of undergraduate students tackle non-routine mathematical problems during a problem-solving course. The aim of the course is to allow students to experience mathematics as a creative process and to reflect on their own experience. During the course, students are required to produce a written ‘rubric’ of their work, i.e., to document their thoughts as they occur as well as their emotionsduring the process. These ‘rubrics’ were used as the main source of data.Students’ problem-solving processes can be explained as a three-stage process that has been called ‘solutioning’. This process is presented in the six sections below. The first three refer to a common area of concern that can be called‘generating knowledge’. In this way, generating knowledge also includes issues related to ‘key ideas’ and ‘gaining understanding’. The third and the fourth sections refer to ‘generating’ and ‘validating a solution’, respectively. Finally, once solutions are generated and validated, students usually try to improve them further before presenting them as final results. Thus, the last section deals with‘improving a solution’. Although not all students go through all of the stages, it may be said that ‘solutioning’ considers students’ main concerns as they tackle non-routine mathematical problems.
Ciccone, Dana Karen
2010-06-01
Public-private partnerships are widely seen as the future of global health; the only realistic option for achieving results in social challenges like infectious disease, because of the needed innovation, expertise and financing that a multiplicity of stakeholders can together provide. Yet, harnessing that potential requires finding a harmony among the drastically different incentive structures and internal cultures of profit-based companies, public institutions and humanitarian initiatives. While public-private partnerships have accomplished the important task of mobilizing new funding for global health, their growing dominance in governance raises questions about their effectiveness, but in particular, about the problem of accountability posed by their structure. This commentary aims to initiate a discussion around the coordination problem that exists with the employment of partnerships in global health and argues that the remedy is to apply a public goods theory approach to centralizing what is currently a fractured, inefficient, and potentially detrimental system.
Wearable technology. Health-care solutions for a growing global population.
Rutherford, Jesse Jayne
2010-01-01
Wearable technology may provide an integral part of the solution for providing health care to a growing world population that will be strained by a ballooning aging population. By providing a means to conduct telemedicine-the monitoring, recording, and transmission of physiological signals from outside of the hospital-wearable technology solutions could ease the burden on health-care personnel and use hospital space for more emergent or responsive care. In addition, employing wearable technology in professions where workers are exposed to dangers or hazards could help save their lives and protect health-care personnel.
DEFF Research Database (Denmark)
Wang, Minghuan; Ding, Fengfei; Deng, SaiYue
2017-01-01
within 2 weeks of injury, CSF tracers also accumulated within tissue associated with microinfarcts. The effect of diffuse microinfarcts on global glymphatic pathway function was exacerbated in the mice aged 12 months compared with the 2- to 3-month-old mice. These findings indicate that glymphatic...
On The Solution Of N-Person Cooperative Games | Chigbu | Global ...
African Journals Online (AJOL)
Global Journal of Mathematical Sciences. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 7, No 1 (2008) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected ...
Global payment for health services as a solution in the financial crisis in Europe
Schrijvers, Guus J.P.
2012-01-01
In these financial difficult years many European governments used global ceilings to control costs of health services. Two scenarios are thinkable. The first is that all individual providers get a budget for their own costs: general practitioners, specialists, hospitals, nursing homes and mental
On The Solution Of N-Person Cooperative Games | Chigbu | Global ...
African Journals Online (AJOL)
The Shapley value approach was therefore chosen as the better one for allocation (the value of the game) to an N-person cooperative game. Keywords: Characteristic Function; Coalition; Constant Sum Game; Imputation; Player ; Payoff; Strategy; The Core Global Journal of Mathematical Sciences Vol. 7 (1) 2008: pp. 49-52 ...
Scipal, K.; Holmes, T.R.H.; de Jeu, R.A.M.; Naeimi, V.; Wagner, W.W.
2008-01-01
In the last few years, research made significant progress towards operational soil moisture remote sensing which lead to the availability of several global data sets. For an optimal use of these data, an accurate estimation of the error structure is an important condition. To solve for the
International Nuclear Information System (INIS)
Taguchi, Satoshi; Kondo, Masanari; Mori, Hiroki; Aramata, Akiko
2013-01-01
Highlights: • Zn upd was studied on Au(1 1 1) electrode in weakly acidic solutions at pH ≃ 4. • Anion co-adsorption with upd Zn was investigated with oxianions and halide anions. • No co-adsorption of halide on upd Zn progressed in the solution with halide. • Surface complex adlayer of zinc–phosphate was formed in Zn upd at pH ≃ 4. • The surface complex was ZnHPO 4 adsorbed with mono-electron transfer. -- Abstract: The underpotential deposition (upd) of zinc was studied on Au(1 1 1) electrode in weakly acidic solutions by voltammetry. The difference of anion co-adsorption strength was investigated on upd Zn in the solutions containing phosphate, sulfate, perchlorate, and halides. The order of anion co-adsorption strength was found to be phosphate > sulfate, phosphate ≫ perchlorate, and phosphate ≫ halides. We present the electrochemical evidence that no co-adsorption of halide progresses on upd Zn at E > −0.7 V (vs. SCE) in spite of the relatively high adsorbability of halide on Au(1 1 1). In 0.1 M KH 2 PO 4 (pH = 4.4), the amount of charge density of the upd Zn stripping corresponded to that of 1/3 monolayer of the Zn adlayer formed as a result of mono-electron transfer between −0.35 V and −0.6 V. The coverage was coincident with that inferred from the (√3 × √3)R30° STM image reported by us in the same condition. The formation of zinc–oxianion (phosphate and sulfate) surface complexes by Zn upd was proposed base on the difference of complex formation constants among the related zinc–anion complexes. Identification of the zinc–phosphate surface complex was thermodynamically carried out around pH = 4 with a Nernst equation, where the shifts of Zn upd peak potential were investigated with the concentration changes of Zn 2+ , H 2 PO 4 − , and H + under an imaginarily reversible condition. The formation of ZnHPO 4 surface complex was concluded in the Zn upd with mono-electron transfer and explained a recent XAS analysis, which
Czech Academy of Sciences Publication Activity Database
Ondreját, Martin
2006-01-01
Roč. 6, č. 1 (2006), s. 23-52 ISSN 0219-4937 R&D Projects: GA ČR(CZ) GA201/01/1197 Institutional research plan: CEZ:AV0Z10190503 Keywords : stochastic wave equation * spatially homogeneous Wiener process * martingale solution Subject RIV: BA - General Mathematics
Directory of Open Access Journals (Sweden)
Maxim Olegovich Korpusov
2012-07-01
Full Text Available In this article the initial-boundary-value problem for generalized dissipative high-order equation of Klein-Gordon type is considered. We continue our study of nonlinear hyperbolic equations and systems with arbitrary positive energy. The modified concavity method by Levine is used for proving blow-up of solutions.
Andru?cã Maria Carmen
2013-01-01
The field of globalization has highlighted an interdependence implied by a more harmonious understanding determined by the daily interaction between nations through the inducement of peace and the management of streamlining and the effectiveness of the global economy. For the functioning of the globalization, the developing countries that can be helped by the developed ones must be involved. The international community can contribute to the institution of the development environment of the gl...
Li, Bing; Li, Yongkun; Zhang, Xuemei
2016-01-01
In this paper, by using the existence of the exponential dichotomy of linear dynamic equations on time scales and the theory of calculus on time scales, we study the existence and global exponential stability of periodic solutions for a class of n-dimensional neutral dynamic equations on time scales. We also present an example to illustrate the feasibility of our results. The results of this paper are completely new and complementary to the previously known results even in both the case of differential equations (time scale [Formula: see text]) and the case of difference equations (time scale [Formula: see text]).
Wen, Huanyao; Zhu, Limei
2018-02-01
In this paper, we consider the Cauchy problem for a two-phase model with magnetic field in three dimensions. The global existence and uniqueness of strong solution as well as the time decay estimates in H2 (R3) are obtained by introducing a new linearized system with respect to (nγ -n˜γ , n - n ˜ , P - P ˜ , u , H) for constants n ˜ ≥ 0 and P ˜ > 0, and doing some new a priori estimates in Sobolev Spaces to get the uniform upper bound of (n - n ˜ ,nγ -n˜γ) in H2 (R3) norm.
Global communication schemes for the numerical solution of high-dimensional PDEs
DEFF Research Database (Denmark)
Hupp, Philipp; Heene, Mario; Jacob, Riko
2016-01-01
The numerical treatment of high-dimensional partial differential equations is among the most compute-hungry problems and in urgent need for current and future high-performance computing (HPC) systems. It is thus also facing the grand challenges of exascale computing such as the requirement...... to reduce global communication. To cope with high dimensionalities we employ a hierarchical discretization scheme, the sparse grid combination technique. Based on an extrapolation scheme, the combination technique additionally mitigates the need for global communication: multiple and much smaller problems...... with the experiments. The model can be used to predict the runtime of the reduce/broadcast step for dimensionalities that are yet out of scope on current supercomputers....
Nuclear energy, a solution in the struggle against global warming in quest of recognition
International Nuclear Information System (INIS)
Faudon, Valerie
2014-01-01
In this article, the author first comments assessments of the continuous increase of greenhouse gas emissions as they appear in the IPCC report of September 2013 and in the results published by the Global Carbon Project. She also evokes the commitments in emission reductions in compliance with the Kyoto Protocol and some dramatic consequences global warming may have according to the IPCC scenarios. Then, she addresses the share of nuclear energy in energy production and outlines its stakes and benefits in terms of greenhouse gas emissions. She notices that international bodies (European Commission, World Bank) do not mention nuclear energy in their plan for energy production development, but mainly rely on the development of renewable energies. The author then outlines the reasons why the development of renewable energies does not necessarily goes with the reduction of greenhouse gas emissions. She also notices that a new generation of ecologists considers nuclear energy as a tool to struggle against climate warming
Burns, Mary
2013-01-01
The number of U.S. teachers participating in some form of distance education is on the rise, yet compared to many nations, distance-based professional learning is fairly new in the U.S. What are common elements of effective global distance education for teachers, and what lessons do they hold for those who design similar programs in the U.S.? Over…
Conservation and fusion as solutions for the greenhouse or global warming effect
International Nuclear Information System (INIS)
Mark, J.W.K.
1992-01-01
The US and other countries are expected to spend trillion dollar sums for power plants in the next decades. Just in the coming decade, the US oil and natural gas production are expected to decline. The US does have abundant supplies of coal. But as has become apparent because of the effects of chlorofluorocarbons (CFC's) on ozone in the atmosphere, the effects of human activity on the earth's global environment has already reached an alarming level. A likely more dangerous prospect awaits as one contemplates the effects on the global climate due to rapid increase of heat trapping gases in the atmosphere. Half of this increase arises from energy activity, another quarter from industrial activity (almost entirely due to CFC's). The important and much emphasized effect of deforestation is only a 14% effect at present and agricultural activities contribute another 13%. For the US midwest, which dominates the world trade in basic cereals due to favorable climate and soil conditions, ''Murphy's Law of Applied Statistics'' would be sufficient to imply that any weather changes would lead to less favorable agricultural conditions. The effects of global agricultural failures coupled to increased energy costs could feed back into more rapid human economic activities that lead to accelerated climate changes. Losses are also expected along low lying coastal areas such as near the Indian Ocean, the coastal states, for example Florida, but also elsewhere. And there are other such nonlinear feedback factors which could accelerate the timescale of global warming. Since energy consumption in the US is some five times that of Japan, a rapid conservation program is a must, e.g. in more efficient electric lighting. But for the intermediate term, it can be argued that the US must simultaneously phase in fusion or other similar non-hydrocarbon-based energy technologies. Easily usable oil and natural gas should eventually be reserved for the petrochemical industries
On global asymptotic stability of solutions of a system of ordinary differential equations
Filimonov, M. Yu.
2017-12-01
To investigate global asymptotic stability in general of an equilibrium position of an autonomous system of ordinary differential equations, considered by V.A. Pliss, a function different from the Lyapunov functions is applied. V.A. Pliss proved that for this system it is impossible to construct the Lyapunov function as a sum of a quadratic form and an integral of some nonlinear function defined by the right-hand side of the system.
Benefit Sharing in a Global Context: Working Towards Solutions for Implementation.
Hurst, Daniel J
2017-08-01
Due to the state of globalized clinical research, questions have been raised as to what, if any, benefits those who contribute to research should receive. One model for compensating research participants is "benefit sharing," and the basic premise is that, as a matter of justice, those who contribute to scientific research should share in its benefits. While incorporated into several international documents for over two decades, benefit sharing has only been sparsely implemented. This analysis begins by addressing the concept of benefit sharing, its historical development, and how it has been applied in the context of virus sharing for influenza research. The second portion of this analysis presents recommendations for ensuring benefit sharing. These recommendations are threefold: 1) an emphasis on social pressure, 2) the revision of international documents as means to ensure benefit sharing, and 3) greater collaboration between sponsor IRB and host country IRB. Because clinical research is a globalized industry, a global model will be proposed in the second that focuses on collaboration between the sponsor and host country. This collaboration is vital in order to ensure that proper forms of benefit sharing are accomplished as a matter of justice. © 2016 John Wiley & Sons Ltd.
Fitting Flux Ropes to a Global MHD Solution: A Comparison of Techniques. Appendix 1
Riley, Pete; Linker, J. A.; Lionello, R.; Mikic, Z.; Odstrcil, D.; Hidalgo, M. A.; Cid, C.; Hu, Q.; Lepping, R. P.; Lynch, B. J.
2004-01-01
Flux rope fitting (FRF) techniques are an invaluable tool for extracting information about the properties of a subclass of CMEs in the solar wind. However, it has proven difficult to assess their accuracy since the underlying global structure of the CME cannot be independently determined from the data. In contrast, large-scale MHD simulations of CME evolution can provide both a global view as well as localized time series at specific points in space. In this study we apply 5 different fitting techniques to 2 hypothetical time series derived from MHD simulation results. Independent teams performed the analysis of the events in "blind tests", for which no information, other than the time series, was provided. F rom the results, we infer the following: (1) Accuracy decreases markedly with increasingly glancing encounters; (2) Correct identification of the boundaries of the flux rope can be a significant limiter; and (3) Results from techniques that infer global morphology must be viewed with caution. In spite of these limitations, FRF techniques remain a useful tool for describing in situ observations of flux rope CMEs.
Fitting Flux Ropes to a Global MHD Solution: A Comparison of Techniques
Riley, Pete; Linker, J. A.; Lionello, R.; Mikic, Z.; Odstrcil, D.; Hidalgo, M. A.; Cid, C.; Hu, Q.; Lepping, R. P.; Lynch, B. J.;
2004-01-01
Flux rope fitting (FRF) techniques are an invaluable tool for extracting information about the properties of a sub-class of coronal mass ejections (CMEs) in the solar wind. However, it has proven difficult to assess their accuracy since the underlying global structure of the CME cannot be independently determined from the data. In contrast, large-scale MHD simulations of CME evolution can provide both a global view as well as localized time series at specific points in space. In this study we apply five different fitting techniques to two hypothetical time series derived from MHD simulation results. Independent teams performed the analysis of the events in "blind tests", for which no information, other than time series, was provided. From the results, we infer the following: 1) Accuracy decreases markedly with increasingly glancing encounters; 2) Correct identification of the boundaries of the flux rope can be a significant limiter; 3) Results from techniques that infer global morphology must be viewed with caution. In spite of these limitations, FRF techniques remain a useful tool for describing in situ observations of flux rope CMEs.
Global existence and decay of solutions of a nonlinear system of wave equations
Said-Houari, Belkacem
2012-03-01
This work is concerned with a system of two wave equations with nonlinear damping and source terms acting in both equations. Under some restrictions on the nonlinearity of the damping and the source terms, we show that our problem has a unique local solution. Also, we prove that, for some restrictions on the initial data, the rate of decay of the total energy is exponential or polynomial depending on the exponents of the damping terms in both equations.
Moment-tensor solutions estimated using optimal filter theory: Global seismicity, 2001
Sipkin, S.A.; Bufe, C.G.; Zirbes, M.D.
2003-01-01
This paper is the 12th in a series published yearly containing moment-tensor solutions computed at the US Geological Survey using an algorithm based on the theory of optimal filter design (Sipkin, 1982 and Sipkin, 1986b). An inversion has been attempted for all earthquakes with a magnitude, mb or MS, of 5.5 or greater. Previous listings include solutions for earthquakes that occurred from 1981 to 2000 (Sipkin, 1986b; Sipkin and Needham, 1989, Sipkin and Needham, 1991, Sipkin and Needham, 1992, Sipkin and Needham, 1993, Sipkin and Needham, 1994a and Sipkin and Needham, 1994b; Sipkin and Zirbes, 1996 and Sipkin and Zirbes, 1997; Sipkin et al., 1998, Sipkin et al., 1999, Sipkin et al., 2000a, Sipkin et al., 2000b and Sipkin et al., 2002).The entire USGS moment-tensor catalog can be obtained via anonymous FTP at ftp://ghtftp.cr.usgs.gov. After logging on, change directory to “momten”. This directory contains two compressed ASCII files that contain the finalized solutions, “mt.lis.Z” and “fmech.lis.Z”. “mt.lis.Z” contains the elements of the moment tensors along with detailed event information; “fmech.lis.Z” contains the decompositions into the principal axes and best double-couples. The fast moment-tensor solutions for more recent events that have not yet been finalized and added to the catalog, are gathered by month in the files “jan01.lis.Z”, etc. “fmech.doc.Z” describes the various fields.
Wrong effects of apparent sustainable solutions. The Dutch impact on global biodiversity
International Nuclear Information System (INIS)
Rood, T.; Alkemade, R.
2005-01-01
What is the value of sustainable development in a specific country if imported products have negative effects in the country from where those products were imported. Apparently sustainable solutions in one's own country might have negative effects somewhere else, sooner or later. A clear picture of the ecological claim of a country is one of the methods to find the right way towards a sustainable future [nl
Li, Yongkun; Liu, Chunchao; Zhu, Lifei
2005-03-01
By using the continuation theorem of coincidence degree theory and constructing suitable Lyapunov functions, we study the existence and stability of periodic solution for shunting inhibitory cellular neural networks (SICNNs) with delays x˙ij(t)=-aij(t)xij(t)-∑Bkl∈Nr(i,j)Bijkl(t)fij(xkl(t))xij(t)-∑Ckl∈Nr(i,j)Cijkl(t)gij(xkl(t-τkl))xij(t)+Lij(t).
Hamdy, Hossam
2017-08-01
The shortage of a competent health workforce is a global challenge. However, its manifestations and proposed solutions are very much context related (i.e., local). In addition to the shortage of health professionals, the quality of health professions education programs, institutions, and graduates, and how to measure quality, are also problematic. Commonly used metrics like the Credit Hours System and the European Credit Transfer and Accumulation System have limitations (e.g., being more focused on quantity than quality).In this Invited Commentary, the author discusses the need to revisit quality measurements in health professions education and the issue of whether the private sector has a role to play in narrowing the ever-increasing gap between the demand for health care professionals and the health care workforce shortage.
Directory of Open Access Journals (Sweden)
T. Sreenivasu
2016-12-01
Full Text Available The solid solutions of (1−x LaFeO3–xBaTiO3 (0.0≤x≤0.25 have been synthesized successfully by the conventional solid-state reaction method. Room temperature (RT X-ray diffraction studies reveal the stabilization of orthorhombic phase with Pbnm space group. Complete solubility in the perovskite series was demonstrated up to x=0.25. The dielectric permittivity shows colossal dielectric constant (CDC at RT. The doping of BaTiO3 in LaFeO3 exhibit pronounced CDC up to a composition x=0.15, further it starts to decrease. The frequency-dependent dielectric loss exhibits polaronic conduction, which can attribute to presence of multiple valence of iron. The relaxation frequency and polaronic conduction mechanism was shifted towards RT as function of x. Moreover, large magnetic moment with weak ferromagnetic behavior is observed in doped LaFeO3 solid solution, which might be the destruction of spin cycloid structure due to insertion of Ti in Fe–O–Fe network of LaFeO3.
Sreenivasu, T.; Tirupathi, P.; Prabahar, K.; Suryanarayana, B.; Chandra Mouli, K.
The solid solutions of (1-x) LaFeO3-xBaTiO3 (0.0≤x≤0.25) have been synthesized successfully by the conventional solid-state reaction method. Room temperature (RT) X-ray diffraction studies reveal the stabilization of orthorhombic phase with Pbnm space group. Complete solubility in the perovskite series was demonstrated up to x=0.25. The dielectric permittivity shows colossal dielectric constant (CDC) at RT. The doping of BaTiO3 in LaFeO3 exhibit pronounced CDC up to a composition x=0.15, further it starts to decrease. The frequency-dependent dielectric loss exhibits polaronic conduction, which can attribute to presence of multiple valence of iron. The relaxation frequency and polaronic conduction mechanism was shifted towards RT as function of x. Moreover, large magnetic moment with weak ferromagnetic behavior is observed in doped LaFeO3 solid solution, which might be the destruction of spin cycloid structure due to insertion of Ti in Fe-O-Fe network of LaFeO3.
Global exponential stability of periodic solution for shunting inhibitory CNNs with delays
International Nuclear Information System (INIS)
Li Yongkun; Liu Chunchao; Zhu Lifei
2005-01-01
By using the continuation theorem of coincidence degree theory and constructing suitable Lyapunov functions, we study the existence and stability of periodic solution for shunting inhibitory cellular neural networks (SICNNs) with delays x-bar ij (t)=-a ij (t)x ij (t)--bar B kl -bar Nr(i,j)B ij kl (t)f ij (x kl (t))x ij (t)--bar C kl -bar Nr(i,j)C ij kl (t)g ij (x kl (t-τ kl ))x ij (t)+L ij (t)
Rare earth elements in sedimentary phosphate deposits: Solution to the global REE crisis?
Emsbo, Poul; McLaughlin, Patrick I.; Breit, George N.; du Bray, Edward A.; Koenig, Alan E.
2015-01-01
The critical role of rare earth elements (REEs), particularly heavy REEs (HREEs), in high-tech industries has created a surge in demand that is quickly outstripping known global supply and has triggered a worldwide scramble to discover new sources. The chemical analysis of 23 sedimentary phosphate deposits (phosphorites) in the United States demonstrates that they are significantly enriched in REEs. Leaching experiments using dilute H2SO4 and HCl, extracted nearly 100% of their total REE content and show that the extraction of REEs from phosphorites is not subject to the many technological and environmental challenges that vex the exploitation of many identified REE deposits. Our data suggest that phosphate rock currently mined in the United States has the potential to produce a significant proportion of the world's REE demand as a byproduct. Importantly, the size and concentration of HREEs in some unmined phosphorites dwarf the world's richest REE deposits. Secular variation in phosphate REE contents identifies geologic time periods favorable for the formation of currently unrecognized high-REE phosphates. The extraordinary endowment, combined with the ease of REE extraction, indicates that such phosphorites might be considered as a primary source of REEs with the potential to resolve the global REE (particularly for HREE) supply shortage.
Climate change and the role of nuclear power - contributions to a global solution
International Nuclear Information System (INIS)
McKechnie, A.J.
1990-01-01
The threat of global climate change is a challenge to those who decide on energy policy. If we are complacent and the worst case scenario materializes, our descendants could be faced with unprecedented problems that would impose massive costs. On the other hand, it is our generation which would suffer if substantial resources were devoted to addressing a problem that did not turn out to be serious. Fortunately, the choice is not a stark as this. There are options such as increased energy efficiency and clean fuels that are economically justified before their environmental benefits are considered. These options are the first priority for addressing climate change. What will be the contribution of nuclear energy? In developing countries it is likely to be small. In the industrialized world, where the cost of capital is lower, the role of nuclear will depend on construction and operating performance of the industry, and the level of public confidence. New nuclear technologies that are inherently safe and small modular designs could transform the nuclear option if costs are competitive with other energy sources. The nuclear option is one that should be kept alive in case a global environmental crisis is forced upon us. (orig.)
Plane waves with weak singularities
International Nuclear Information System (INIS)
David, Justin R.
2003-03-01
We study a class of time dependent solutions of the vacuum Einstein equations which are plane waves with weak null singularities. This singularity is weak in the sense that though the tidal forces diverge at the singularity, the rate of divergence is such that the distortion suffered by a freely falling observer remains finite. Among such weak singular plane waves there is a sub-class which does not exhibit large back reaction in the presence of test scalar probes. String propagation in these backgrounds is smooth and there is a natural way to continue the metric beyond the singularity. This continued metric admits string propagation without the string becoming infinitely excited. We construct a one parameter family of smooth metrics which are at a finite distance in the space of metrics from the extended metric and a well defined operator in the string sigma model which resolves the singularity. (author)
Fair Trade as a Solution for Inequality on the Global Market - Corporate Perspective
Directory of Open Access Journals (Sweden)
Sandra Lovric
2016-03-01
Full Text Available New alternatives to free trade are evolving at the global market; their aim is to bring more ethics and morality into the relations between the trading parties (producers, corporations and buyers. This article analyses one of such alternatives i.e. Fair Trade from the perspective of influencing change of corporate politics. Due to the rising awareness of buyers about the origin of goods and the initiatives of forcing corporations into changing their practices based on unethical treatment of workers in the 3rd world countries, alternative ways of trade are becoming part of traditional corporate environment in the free trade chain. By elaborating fundamental principles of certification process, the article gives an answer to the question of creation of added ethical value in the aspect of positioning corporations in the “new economy”.
WASTE HEAT RECOVERY IN HEAT PUMP SYSTEMS: SOLUTION TO REDUCE GLOBAL WARMING
Directory of Open Access Journals (Sweden)
Y. Baradey
2015-11-01
Full Text Available Energy conversion technologies, where waste heat recovery systems are included, have received significant attention in recent years due to reasons that include depletion of fossil fuel, increasing oil prices, changes in climatic conditions, and global warming. For low temperature applications, there are many sources of thermal waste heat, and several recovery systems and potential useful applications have been proposed by researchers [1-4]. In addition, many types of equipment are used to recover waste thermal energy from different systems at low, medium, and high temperature applications, such as heat exchangers, waste heat recovery boiler, thermo-electric generators, and recuperators. In this paper, the focus is on waste heat recovery from air conditioners, and an efficient application of these energy resources. Integration of solar energy with heat pump technologies and major factors that affect the feasibility of heat recovery systems have been studied and reviewed as well. KEYWORDS: waste heat recovery; heat pump.
Luthcke, Scott B.; Sabaka, T. J.; Loomis, B. D.; Arendt, A. A.; McCarthy, J. J.; Camp, J.
2013-01-01
We have determined the ice mass evolution of the Antarctica and Greenland ice sheets (AIS and GIS) and Gulf of Alaska (GOA) glaciers from a new GRACE global solution of equal-area surface mass concentration parcels (mascons) in equivalent height of water. The mascons were estimated directly from the reduction of the inter-satellite K-band range-rate (KBRR) observations, taking into account the full noise covariance, and formally iterating the solution. The new solution increases signal recovery while reducing the GRACE KBRR observation residuals. The mascons were estimated with 10 day and 1 arc degree equal-area sampling, applying anisotropic constraints. An ensemble empirical mode decomposition adaptive filter was applied to the mascon time series to compute annual mass balances. The details and causes of the spatial and temporal variability of the land-ice regions studied are discussed. The estimated mass trend over the total GIS, AIS and GOA glaciers for the time period 1 December 2003 to 1 December 2010 is -380 plus or minus 31 Gt a(exp -1), equivalent to -1.05 plus or minus 0.09 mma(exp -1) sea-level rise. Over the same time period we estimate the mass acceleration to be -41 plus or minus 27 Gt a(exp -2), equivalent to a 0.11 plus or minus 0.08 mm a(exp -2) rate of change in sea level. The trends and accelerations are dependent on significant seasonal and annual balance anomalies.
Directory of Open Access Journals (Sweden)
Fabrício Bertini Pasquot Polido
2017-05-01
Full Text Available http://dx.doi.org/10.5007/2177-7055.2017v38n75p157 The article explores some issues regarding the interface between international electronic contracts and private international law. Today, thanks to the internet, crossborder commercial transactions, previously unthinkable, become possible. However, as to the inherent specificities of the internet, contracts having connecting factors offer bring questions related to determination of law applicable or even validity issues, among others. Unlike the extensive regulatory agenda furthered by the United Nations Commission on International Trade Law on the subject, Brazil needs to assess existing initiatives and designing the necessary solutions for ensuring legal certainty in this field.
Global exponential stability of periodic solution for shunting inhibitory CNNs with delays
Energy Technology Data Exchange (ETDEWEB)
Li Yongkun [Department of Mathematics, Yunnan University, Kunming, Yunnan 650091 (China)]. E-mail: yklie@ynu.edu.cn; Liu Chunchao [Department of Mathematics, Yunnan University, Kunming, Yunnan 650091 (China); Zhu Lifei [Department of Mathematics, Yunnan University, Kunming, Yunnan 650091 (China)
2005-03-28
By using the continuation theorem of coincidence degree theory and constructing suitable Lyapunov functions, we study the existence and stability of periodic solution for shunting inhibitory cellular neural networks (SICNNs) with delays x-bar {sub ij}(t)=-a{sub ij}(t)x{sub ij}(t)--bar B{sup kl}-bar Nr(i,j)B{sub ij}{sup kl}(t)f{sub ij}(x{sub kl}(t))x{sub ij}(t)--bar C{sup kl}-bar Nr(i,j)C{sub ij}{sup kl}(t)g{sub ij}(x{sub kl}(t-{tau}{sub kl}))x{sub ij}(t)+L{sub ij}(t)
Big Data solution for CTBT monitoring: CEA-IDC joint global cross correlation project
Bobrov, Dmitry; Bell, Randy; Brachet, Nicolas; Gaillard, Pierre; Kitov, Ivan; Rozhkov, Mikhail
2014-05-01
Waveform cross-correlation when applied to historical datasets of seismic records provides dramatic improvements in detection, location, and magnitude estimation of natural and manmade seismic events. With correlation techniques, the amplitude threshold of signal detection can be reduced globally by a factor of 2 to 3 relative to currently standard beamforming and STA/LTA detector. The gain in sensitivity corresponds to a body wave magnitude reduction by 0.3 to 0.4 units and doubles the number of events meeting high quality requirements (e.g. detected by three and more seismic stations of the International Monitoring System (IMS). This gain is crucial for seismic monitoring under the Comprehensive Nuclear-Test-Ban Treaty. The International Data Centre (IDC) dataset includes more than 450,000 seismic events, tens of millions of raw detections and continuous seismic data from the primary IMS stations since 2000. This high-quality dataset is a natural candidate for an extensive cross correlation study and the basis of further enhancements in monitoring capabilities. Without this historical dataset recorded by the permanent IMS Seismic Network any improvements would not be feasible. However, due to the mismatch between the volume of data and the performance of the standard Information Technology infrastructure, it becomes impossible to process all the data within tolerable elapsed time. To tackle this problem known as "BigData", the CEA/DASE is part of the French project "DataScale". One objective is to reanalyze 10 years of waveform data from the IMS network with the cross-correlation technique thanks to a dedicated High Performance Computer (HPC) infrastructure operated by the Centre de Calcul Recherche et Technologie (CCRT) at the CEA of Bruyères-le-Châtel. Within 2 years we are planning to enhance detection and phase association algorithms (also using machine learning and automatic classification) and process about 30 terabytes of data provided by the IDC to
Global oral health inequalities in incidence and outcomes for oral cancer: causes and solutions.
Johnson, N W; Warnakulasuriya, S; Gupta, P C; Dimba, E; Chindia, M; Otoh, E C; Sankaranarayanan, R; Califano, J; Kowalski, L
2011-05-01
The mouth and oropharynx are among the ten most common sites affected by cancer worldwide, but global incidence varies widely. Five-year survival rates exceed 50% in only the best treatment centers. Causes are predominantly lifestyle-related: Tobacco, areca nut, alcohol, poor diet, viral infections, and pollution are all important etiological factors. Oral cancer is a disease of the poor and dispossessed, and reducing social inequalities requires national policies co-ordinated with wider health and social initiatives - the common risk factor approach: control of the environment; safe water; adequate food; public and professional education about early signs and symptoms; early diagnosis and intervention; evidence-based treatments appropriate to available resources; and thoughtful rehabilitation and palliative care. Reductions in inequalities, both within and between countries, are more likely to accrue from the application of existing knowledge in a whole-of-society approach. Basic research aimed at determining individual predisposition and acquired genetic determinants of carcinogenesis and tumor progression, thus allowing for targeted therapies, should be pursued opportunistically.
GRIM5-C1: Combination solution of the global gravity field to degree and order 120
Gruber, Thomas; Bode, Albert; Reigber, Christoph; Schwintzer, Peter; Balmino, Georges; Biancale, Richard; Lemoine, Jean-Michel
2000-12-01
The new satellite Earth gravity field model GRIM5-S1 was recently prepared in a joint GFZ and GRGS effort. Based on this satellite solution and terrestrial and altimetric gravity anomalies from NIMA, a combined model GRIM5-C1, with full variance-covariance matrix up to degree and order 120, was computed. Surface gravity and altimetric gravity data are corrected for several systematic effects, such as ellipsoidal corrections and aliasing. A weighting scheme for gravity anomalies, according to their given standard deviations was developed. From each data set full normal equations were set up and finally combined with the GRIM5-S1 normals. To take into account good information from the satellite-only model a procedure was developed to identify such coefficients and appropriately weighed them in the final normal equation system. Internal error propagation and comparisons to external data sets show, that the GRIM5-C1 model represents the best state of long wavelength gravity field models.
DEFF Research Database (Denmark)
Plum, Maja
Globalization is often referred to as external to education - a state of affair facing the modern curriculum with numerous challenges. In this paper it is examined as internal to curriculum; analysed as a problematization in a Foucaultian sense. That is, as a complex of attentions, worries, ways...... of reasoning, producing curricular variables. The analysis is made through an example of early childhood curriculum in Danish Pre-school, and the way the curricular variable of the pre-school child comes into being through globalization as a problematization, carried forth by the comparative practices of PISA...
F. Gerard Adams
2008-01-01
The rapid globalization of the world economy is causing fundamental changes in patterns of trade and finance. Some economists have argued that globalization has arrived and that the world is â€œflatâ€ . While the geographic scope of markets has increased, the author argues that new patterns of trade and finance are a result of the discrepancies between â€œoldâ€ countries and â€œnewâ€ . As the differences are gradually wiped out, particularly if knowledge and technology spread worldwide, the t...
Rodriguez, G Y; Valverde-Ramírez, M; Mendes, C E; Béttega, R; Badino, A C
2015-11-01
Global variables play a key role in evaluation of the performance of pneumatic bioreactors and provide criteria to assist in system selection and design. The purpose of this work was to use experimental data and computational fluid dynamics (CFD) simulations to determine the global performance parameters gas holdup ([Formula: see text]) and volumetric oxygen transfer coefficient (k L a), and conduct an analysis of liquid circulation velocity, for three different geometries of pneumatic bioreactors: bubble column, concentric-tube airlift, and split tube airlift. All the systems had 5 L working volumes and two Newtonian fluids of different viscosities were used in the experiments: distilled water and 10 cP glycerol solution. Considering the high oxygen demand in certain types of aerobic fermentations, the assays were carried out at high flow rates. In the present study, the performances of three pneumatic bioreactors with different geometries and operating with two different Newtonian fluids were compared. A new CFD modeling procedure was implemented, and the simulation results were compared with the experimental data. The findings indicated that the concentric-tube airlift design was the best choice in terms of both gas holdup and volumetric oxygen transfer coefficient. The CFD results for gas holdup were consistent with the experimental data, and indicated that k L a was strongly influenced by bubble diameter and shape.
Phillips, Peter W B
2016-01-01
For almost a generation now, scientists and policy makers have enthusiastically advanced genetically modified (GM) crops as a solution to both global food security and, specifically, the micronutrient needs of the hidden hungry. While genetic modification offers the prospect of overcoming technological barriers to food security, the gap between the vision and reality remains large. This chapter examines the impact of GM crops at three levels. Undoubtedly, at the micro level, bio-fortification offers a real opportunity to enhance the availability of micronutrients. However, the inexorable 'research sieve' ruthlessly culls most technical candidates in the agri-food system. GM bio-fortified foods, such as Golden RiceTM, remain only a promise. At the meso level, GM crops have generated benefits for both producers and consumers who have adopted GM crops, but given that the technology has been differentially applied to maize, the average diet for the food insecure has become somewhat less balanced. Finally, while GM crops have increased yields and the global food supply, these have come at the cost of more complex and costly trade and market systems, which impair access and availability. In essence, while biotechnology offers some tantalizing technological prospects, the difficulties of getting the corresponding benefits to the most needy have dampened some of the enthusiasm. © 2016 S. Karger AG, Basel.
Anand, Sonia S.; Hawkes, Corinna; de Souza, Russell J.; Mente, Andrew; Dehghan, Mahshid; Nugent, Rachel; Zulyniak, Michael A.; Weis, Tony; Bernstein, Adam M.; Krauss, Ronald; Kromhout, Daan; Jenkins, David J.A.; Malik, Vasanti; Martinez-Gonzalez, Miguel A.; Mozafarrian, Dariush; Yusuf, Salim; Willett, Walter C.; Popkin, Barry M
2015-01-01
Major scholars in the field, based on a 3-day consensus, created an in-depth review of current knowledge on the role of diet in CVD, the changing global food system and global dietary patterns, and potential policy solutions. Evidence from different countries, age/race/ethnicity/socioeconomic groups suggest the health effects studies of foods, macronutrients, and dietary patterns on CVD appear to be far more consistent though regional knowledge gaps are highlighted. There are large gaps in knowledge about the association of macronutrients to CVD in low- and middle-income countries (LMIC), particularly linked with dietary patterns are reviewed. Our understanding of foods and macronutrients in relationship to CVD is broadly clear; however major gaps exist both in dietary pattern research and ways to change diets and food systems. Based on the current evidence, the traditional Mediterranean-type diet, including plant foods/emphasizing plant protein sources, provides a well-tested healthy dietary pattern to reduce CVD. PMID:26429085
Riley, Douglas A.
We study the three-dimensional incompressible Navier- Stokes equations in a domain of the form W'×(0,e) . First, we assume W' is a C3 bounded domain and impose no-slip boundary conditions on 6W'×(0,e ) , and periodic conditions on W'×0,e . Physically, this models fluid flow through a pipe with cross-section W' where the inlet and outlet conditions are assumed periodic. Secondly, we assume W'=(0,l4) ×(0,l5) and impose periodic boundary conditions. This problem is of interest mathematically, and has been more widely considered than the pipe flow problem. For both sets of boundary conditions, we show that a strong solution exists for all time with conditions on the initial data and forcing. We start by recalling that if the forcing function and initial condition do not depend on x3, then a global strong solution exists which also does not depend on x3. Here (x1,x2,x3) ∈W≡W'×( 0,e) . With this observation as motivation, and using an additive decomposition introduced by Raugel and Sell, we split the initial data and forcing into a portion independent of x3 and a remainder. In our first result, we impose a smallness condition on the remainder and assume the forcing function is square- integrable in time as a function into L2(W) . With these assumptions, we prove a global existence theorem that does not require a smallness condition on e or on the portion of the initial condition and forcing independent of x3. However, these quantities do affect the allowable size of the remainder. For our second result, we assume the forcing is only bounded in time as a function into L2(W) . In this case, we need a smallness condition on the initial data, the forcing, and e to obtain global existence. The interesting observation is that the allowable sizes for the initial data and forcing grow as e-->0 . Thus, we obtain a `thin-domain' result as originally obtained by Raugel and Sell. In fact, our results allow the portion of the initial data and forcing independent of x3 to
DEFF Research Database (Denmark)
Plum, Maja
Globalization is often referred to as external to education - a state of affair facing the modern curriculum with numerous challenges. In this paper it is examined as internal to curriculum; analysed as a problematization in a Foucaultian sense. That is, as a complex of attentions, worries, ways...... of reasoning, producing curricular variables. The analysis is made through an example of early childhood curriculum in Danish Pre-school, and the way the curricular variable of the pre-school child comes into being through globalization as a problematization, carried forth by the comparative practices of PISA....... It thus explores the systems of reason that educational comparative practices carry through time; focusing on the way configurations are reproduced and transformed, forming the pre-school child as a central curricular variable....
Shahkarami, Pirouz; Liu, Longcheng; Moreno, Luis; Neretnieks, Ivars
2015-01-01
This study presents an analytical approach to simulate nuclide migration through a channel in a fracture accounting for an arbitrary-length decay chain. The nuclides are retarded as they diffuse in the porous rock matrix and stagnant zones in the fracture. The Laplace transform and similarity transform techniques are applied to solve the model. The analytical solution to the nuclide concentrations at the fracture outlet is governed by nine parameters representing different mechanisms acting on nuclide transport through a fracture, including diffusion into the rock matrices, diffusion into the stagnant water zone, chain decay and hydrodynamic dispersion. Furthermore, to assess how sensitive the results are to parameter uncertainties, the Sobol method is applied in variance-based global sensitivity analyses of the model output. The Sobol indices show how uncertainty in the model output is apportioned to the uncertainty in the model input. This method takes into account both direct effects and interaction effects between input parameters. The simulation results suggest that in the case of pulse injections, ignoring the effect of a stagnant water zone can lead to significant errors in the time of first arrival and the peak value of the nuclides. Likewise, neglecting the parent and modeling its daughter as a single stable species can result in a significant overestimation of the peak value of the daughter nuclide. It is also found that as the dispersion increases, the early arrival time and the peak time of the daughter decrease while the peak value increases. More importantly, the global sensitivity analysis reveals that for time periods greater than a few thousand years, the uncertainty of the model output is more sensitive to the values of the individual parameters than to the interaction between them. Moreover, if one tries to evaluate the true values of the input parameters at the same cost and effort, the determination of priorities should follow a certain
Directory of Open Access Journals (Sweden)
Jay Cooper Beeks
2018-01-01
Full Text Available The problem of finding the method and means of internalizing the costs of externalities has stumped economists since Arthur Pigou first presented this issue in 1920. Since Pigou, several mainstream economists and alternative economists have attempted to further his ideas because of the promise of curbing consumer behaviors and thereby reducing detrimental activities such as the production of greenhouse gases. The current call for a carbon tax to stem the causes of Global Climate Change is just one example of a present day method of internalizing externalities. Of all of the modern day proponents for a carbon tax and other forms of “green fees”, however, Paul Hawken is arguably the most ardent supporter, believing this to be the most effective method of stemming many of humankind’s pollution activities. His best selling book The Ecology of Commerce, A Declaration of Sustainability is examined here further, in order to explore Hawken’s arguments for these kinds of microeconomic solutions and to expand on these ideas to include macroeconomic solutions as well. As Hawken and others have noted, global climate change presents a size issue that must be countered using global forces in addition to microeconomic solutions such as with green fees. This paper explores how global problems such as global climate change can be countered with the aid of international organizations for the benefit of global citizens.
International Nuclear Information System (INIS)
Deshpande, N.G.
1980-01-01
By electro-weak theory is meant the unified field theory that describes both weak and electro-magnetic interactions. The development of a unified electro-weak theory is certainly the most dramatic achievement in theoretical physics to occur in the second half of this century. It puts weak interactions on the same sound theoretical footing as quantum elecrodynamics. Many theorists have contributed to this development, which culminated in the works of Glashow, Weinberg and Salam, who were jointly awarded the 1979 Nobel Prize in physics. Some of the important ideas that contributed to this development are the theory of beta decay formulated by Fermi, Parity violation suggested by Lee and Yang, and incorporated into immensely successful V-A theory of weak interactions by Sudarshan and Marshak. At the same time ideas of gauge invariance were applied to weak interaction by Schwinger, Bludman and Glashow. Weinberg and Salam then went one step further and wrote a theory that is renormalizable, i.e., all higher order corrections are finite, no mean feat for a quantum field theory. The theory had to await the development of the quark model of hadrons for its completion. A description of the electro-weak theory is given
International Nuclear Information System (INIS)
Walecka, J.D.
1983-01-01
Nuclei provide systems where the strong, electomagnetic, and weak interactions are all present. The current picture of the strong interactions is based on quarks and quantum chromodynamics (QCD). The symmetry structure of this theory is SU(3)/sub C/ x SU(2)/sub W/ x U(1)/sub W/. The electroweak interactions in nuclei can be used to probe this structure. Semileptonic weak interactions are considered. The processes under consideration include beta decay, neutrino scattering and weak neutral-current interactions. The starting point in the analysis is the effective Lagrangian of the Standard Model
Directory of Open Access Journals (Sweden)
ANDREEA NICOLAESCU
2011-03-01
Full Text Available Unlike large enterprises, SMEs, especially innovative ones, face increaseddifficulties in the attempt to obtain financing due to the specificity of their activity.This situation calls for the involvement of the state by means of polices aiming atproviding support to this sector, and especially in order to encourage innovation,which can be a solution for increasing Romania’s competitiveness at the global level.Among the methods used to support these ideas, we will list several, from amongthose used in the article: the analysis of statistical data from several complementarysources (including evolution over time – indicators related to SMEs in general (theshare of enterprises, of the workforce, of the turnover, of the added value, in thenational economy etc. and to innovative ones in particular (means for innovation –using own funds or in cooperation; types of innovation – technological or nontechnological,etc.; a comparison on the one hand between the situation in Romaniaand the one in the EU, using indicators calculated as the average of values recorded inthe member states, and, on the other hand, between Romania and other EU membersstates with innovation performances superior or comparable to those of our country;emphasizing the difficulties faced by this sector, especially those concerning access tofinancing, in relation to innovation-related characteristics.
Jin, Jiaying; Ma, Tianyu; Zhang, Yujing; Bai, Guohua; Yan, Mi
2016-08-24
The global rare earth (RE) criticality, especially for those closely-relied Nd/Pr/Dy/Tb in the 2:14:1-typed permanent magnets (PMs), has triggered tremendous attempts to develop new alternatives. Prospective candidates La/Ce with high abundance, however, cannot provide an equivalent performance due to inferior magnetic properties of (La/Ce)2Fe14B to Nd2Fe14B. Here we report high figure-of-merit La/Ce-rich RE-Fe-B PMs, where La/Ce are inhomogeneously distributed among the 2:14:1 phase. The resultant exchange coupling within an individual grain and magnetostatic interactions across grains ensure much superior performance to the La/Ce homogeneously distributed magnet. Maximum energy product (BH)max of 42.2 MGOe is achieved even with 36 wt. % La-Ce incorporation. The cost performance, (BH)max/cost, has been raised by 27.1% compared to a 48.9 MGOe La/Ce-free commercial magnet. The construction of chemical heterogeneity offers recipes to develop commercial-grade PMs using the less risky La/Ce, and also provides a promising solution to the REs availability constraints.
International Nuclear Information System (INIS)
Anon.
1979-01-01
The possibility of the production of weak bosons in the proton-antiproton colliding beam facilities which are currently being developed, is discussed. The production, decay and predicted properties of these particles are described. (W.D.L.).
Lee, T. D.
1970-07-01
While the phenomenon of beta-decay was discovered near the end of the last century, the notion that the weak interaction forms a separate field of physical forces evolved rather gradually. This became clear only after the experimental discoveries of other weak reactions such as muon-decay, muon-capture, etc., and the theoretical observation that all these reactions can be described by approximately the same coupling constant, thus giving rise to the notion of a universal weak interaction. Only then did one slowly recognize that the weak interaction force forms an independent field, perhaps on the same footing as the gravitational force, the electromagnetic force, and the strong nuclear and sub-nuclear forces.
2013-08-01
Stéphane Coen and Miro Erkintalo from the University of Auckland in New Zealand talk to Nature Photonics about their surprising findings regarding a weak long-range interaction they serendipitously stumbled upon while researching temporal cavity solitons.
International Nuclear Information System (INIS)
Daumenov, T.D.; Alizarovskaya, I.M.; Khizirova, M.A.
2001-01-01
The method of the weakly oval electrical field getting generated by the axially-symmetrical field is shown. Such system may be designed with help of the cylindric form coaxial electrodes with the built-in quadrupole duplet. The singularity of the indicated weakly oval lense consists of that it provides the conducting both mechanical and electronic adjustment. Such lense can be useful for elimination of the near-axis astigmatism in the electron-optical system
Camilli, Fabio; Prados, Emmanuel
2011-01-01
International audience; Viscosity solution is a notion of weak solution for a class of partial differential equations of Hamilton-Jacobi type. The range of applications of the notions of viscosity solution and Hamilton-Jacobi equations is enormous, including common class of partial differential equations such as evolutive problems and problems with boundary conditions, equations arising in optimal control theory, differential games, second-order equations arising in stochastic optimal control...
Weak KAM theory for a weakly coupled system of Hamilton–Jacobi equations
Figalli, Alessio
2016-06-23
Here, we extend the weak KAM and Aubry–Mather theories to optimal switching problems. We consider three issues: the analysis of the calculus of variations problem, the study of a generalized weak KAM theorem for solutions of weakly coupled systems of Hamilton–Jacobi equations, and the long-time behavior of time-dependent systems. We prove the existence and regularity of action minimizers, obtain necessary conditions for minimality, extend Fathi’s weak KAM theorem, and describe the asymptotic limit of the generalized Lax–Oleinik semigroup. © 2016, Springer-Verlag Berlin Heidelberg.
Weak KAM for commuting Hamiltonians
International Nuclear Information System (INIS)
Zavidovique, M
2010-01-01
For two commuting Tonelli Hamiltonians, we recover the commutation of the Lax–Oleinik semi-groups, a result of Barles and Tourin (2001 Indiana Univ. Math. J. 50 1523–44), using a direct geometrical method (Stoke's theorem). We also obtain a 'generalization' of a theorem of Maderna (2002 Bull. Soc. Math. France 130 493–506). More precisely, we prove that if the phase space is the cotangent of a compact manifold then the weak KAM solutions (or viscosity solutions of the critical stationary Hamilton–Jacobi equation) for G and for H are the same. As a corollary we obtain the equality of the Aubry sets and of the Peierls barrier. This is also related to works of Sorrentino (2009 On the Integrability of Tonelli Hamiltonians Preprint) and Bernard (2007 Duke Math. J. 136 401–20)
Energy Technology Data Exchange (ETDEWEB)
Abdelaziz, Omar [ORNL; Fricke, Brian A [ORNL; Vineyard, Edward Allan [ORNL
2012-01-01
Commercial refrigeration systems are known to be prone to high leak rates and to consume large amounts of electricity. As such, direct emissions related to refrigerant leakage and indirect emissions resulting from primary energy consumption contribute greatly to their Life Cycle Climate Performance (LCCP). In this paper, an LCCP design tool is used to evaluate the performance of a typical commercial refrigeration system with alternative refrigerants and minor system modifications to provide lower Global Warming Potential (GWP) refrigerant solutions with improved LCCP compared to baseline systems. The LCCP design tool accounts for system performance, ambient temperature, and system load; system performance is evaluated using a validated vapor compression system simulation tool while ambient temperature and system load are devised from a widely used building energy modeling tool (EnergyPlus). The LCCP design tool also accounts for the change in hourly electricity emission rate to yield an accurate prediction of indirect emissions. The analysis shows that conventional commercial refrigeration system life cycle emissions are largely due to direct emissions associated with refrigerant leaks and that system efficiency plays a smaller role in the LCCP. However, as a transition occurs to low GWP refrigerants, the indirect emissions become more relevant. Low GWP refrigerants may not be suitable for drop-in replacements in conventional commercial refrigeration systems; however some mixtures may be introduced as transitional drop-in replacements. These transitional refrigerants have a significantly lower GWP than baseline refrigerants and as such, improved LCCP. The paper concludes with a brief discussion on the tradeoffs between refrigerant GWP, efficiency and capacity.
Kizhner, Semion; Day, John H. (Technical Monitor)
2000-01-01
Post-Processing of data related to a Global Positioning System (GPS) simulation is an important activity in qualification of a GPS receiver for space flight. Because a GPS simulator is a critical resource it is desirable to move off the pertinent simulation data from the simulator as soon as a test is completed. The simulator data files are usually moved to a Personal Computer (PC), where the post-processing of the receiver logged measurements and solutions data and simulated data is performed. Typically post-processing is accomplished using PC-based commercial software languages and tools. Because of commercial software systems generality their general-purpose functions are notoriously slow and more than often are the bottleneck problem even for short duration experiments. For example, it may take 8 hours to post-process data from a 6-hour simulation. There is a need to do post-processing faster, especially in order to use the previous test results as feedback for a next simulation setup. This paper demonstrates that a fast software linear interpolation algorithm is applicable to a large class of engineering problems, like GPS simulation data post-processing, where computational time is a critical resource and is one of the most important considerations. An approach is developed that allows to speed-up post-processing by an order of magnitude. It is based on improving the post-processing bottleneck interpolation algorithm using apriori information that is specific to the GPS simulation application. The presented post-processing scheme was used in support of a few successful space flight missions carrying GPS receivers. A future approach to solving the post-processing performance problem using Field Programmable Gate Array (FPGA) technology is described.
International Nuclear Information System (INIS)
Roberts, B.L.; Booth, E.C.; Gall, K.P.; McIntyre, E.K.; Miller, J.P.; Whitehouse, D.A.; Bassalleck, B.; Hall, J.R.; Larson, K.D.; Wolfe, D.M.; Fickinger, W.J.; Robinson, D.K.; Hallin, A.L.; Hasinoff, M.D.; Measday, D.F.; Noble, A.J.; Waltham, C.E.; Hessey, N.P.; Lowe, J.; Horvath, D.; Salomon, M.
1990-01-01
New measurements of the Σ + and Λ weak radiative decays are discussed. The hyperons were produced at rest by the reaction K - p → Yπ where Y = Σ + or Λ. The monoenergetic pion was used to tag the hyperon production, and the branching ratios were determined from the relative amplitudes of Σ + → pγ to Σ + → pπ 0 and Λ → nγ to Λ → nπ 0 . The photons from weak radiative decays and from π 0 decays were detected with modular NaI arrays. (orig.)
International Nuclear Information System (INIS)
Kudryavtsev, L D
2006-01-01
The problem under consideration concerns when a system of ordinary differential equations reducible to a weakly non-linear system has solutions with the same asymptotic behaviour as solutions of the corresponding homogeneous system. The existence and uniqueness of global solutions to the inhomogeneous system is established in the form of a solution to a homogeneous system of differential equations, in the case when asymptotic initial data is prescribed at the singular points of these systems.
Global Well-posedness of the Spatially Homogeneous Kolmogorov-Vicsek Model as a Gradient Flow
Figalli, Alessio; Kang, Moon-Jin; Morales, Javier
2018-03-01
We consider the so-called spatially homogenous Kolmogorov-Vicsek model, a non-linear Fokker-Planck equation of self-driven stochastic particles with orientation interaction under the space-homogeneity. We prove the global existence and uniqueness of weak solutions to the equation. We also show that weak solutions exponentially converge to a steady state, which has the form of the Fisher-von Mises distribution.
Global attractors for the 2D hyperbolic Cahn–Hilliard equations
Khanmamedov, Azer; Yayla, Sema
2018-02-01
We consider the initial boundary value problem for the hyperbolic relaxation of the 2D Cahn-Hilliard equation with sub-cubic nonlinearity. Under mild regularity conditions on the nonlinearity, we prove the uniform (with respect to the initial data) boundedness of the weak solutions without assuming lower bound condition on the first derivative of the nonlinear term. Then, we prove the existence of the regular global attractor for the weak solutions.
Anderson, Daniel; Hilbert, Kent; Lewis, David
2007-01-01
This candidate solution suggests the use of GPM precipitation observations to enhance the Acadia National Park NLERDSS. Simulated GPM data should provide measurements that would enable analysis of how precipitation affects runoff and nutrient load in the park?s wetlands. This solution benefits society by aiding park and resource managers in making predictions based on hypothetical changes and in identifying effective mitigation scenarios. This solution supports the Coastal Management, Water Management, and Ecological Forecasting National Applications.
Nonstationary weak signal detection based on normalization ...
Indian Academy of Sciences (India)
Haibin Zhang
Time-varying signal; weak signal detection; varying parameters; stochastic resonance. 1. Introduction. In general view, noise ..... the numerical solution for the typical first-order differential equation as Eq. (2). The discrete fourth-rank Runge–Kutta method [27] as follows is applied to solve the equation numerically. x. 0 ¼ dx dt.
Energy Technology Data Exchange (ETDEWEB)
Windsor, C. [Bond Univ. (Australia); McNicholas, P. [Monash Univ. (Australia)
2009-07-01
A large body of scientific evidence indicates that global warming from human induced greenhouse gases (GHG) emissions is producing harmful climate change that will lead to global environmental and economic catastrophe within 10 years. The threat of human induced global warming has been on the international and public policy agenda for several years; for example on 11 December 1998, government representatives of 108 countries signed the United Nations Framework Convention on Climate Change (UNFCCC) an international agreement to reduce global warming or the Kyoto Protocol, with the then exception of the Australian and the United States (U.S.) governments. International action on GHG emissions reduction was thwarted by U.S. and Australian goverments. The then Australian government (1996-2007) surreptitiously funding by vested interests such as the coal industry, had no intention to act even though scientific evidence reported that Australia had begun to experience the detrimental effects of global warming. To fulfil an electoral promise, the center left Labor government signed the Kyoto Protocol on 3 December 2007. To deal with the global warming crisis, the Australian government has proposed an emissions trading scheme now officially called the 'Carbon Pollution Reduction Scheme' or CPRS. The proposed scheme is a cap and trade market mechanism that purportedly encourages businesses to operate more efficiently, thus reducing GHG emissions through price signalling in a government instigated market. Hence credible, transparent and efficient information underpins such a market in a post-Keynes deregulated world. The purpose of this paper is to critically examine the integrity of using current financial and reporting regulation that will oversee and monitor the veracity of newly commoditized carbon financial products, particularly since the global financial crisis has exposed significant financial regulatory weaknesses. Further we contend that current corporate
Veeraraghavan, Srikant; Mazziotti, David A
2014-03-28
We present a density matrix approach for computing global solutions of restricted open-shell Hartree-Fock theory, based on semidefinite programming (SDP), that gives upper and lower bounds on the Hartree-Fock energy of quantum systems. While wave function approaches to Hartree-Fock theory yield an upper bound to the Hartree-Fock energy, we derive a semidefinite relaxation of Hartree-Fock theory that yields a rigorous lower bound on the Hartree-Fock energy. We also develop an upper-bound algorithm in which Hartree-Fock theory is cast as a SDP with a nonconvex constraint on the rank of the matrix variable. Equality of the upper- and lower-bound energies guarantees that the computed solution is the globally optimal solution of Hartree-Fock theory. The work extends a previously presented method for closed-shell systems [S. Veeraraghavan and D. A. Mazziotti, Phys. Rev. A 89, 010502-R (2014)]. For strongly correlated systems the SDP approach provides an alternative to the locally optimized Hartree-Fock energies and densities with a certificate of global optimality. Applications are made to the potential energy curves of C2, CN, Cr2, and NO2.
Energy Technology Data Exchange (ETDEWEB)
Shuman, Craig S. (Reef Check, UCLA)
2003-02-05
Second only to tropical rainforests, coral reefs support one of the world's most diverse natural habitats. Over 350 million individuals depend on coral reef resources for food and income. Unfortunately, the Earth is in the midst of a coral reef crisis. Anthropogenic impacts including overfishing, destructive fishing practices, sedimentation and pollution, as well as global climate change, have served to disrupt the natural processes that maintain the health of these ecosystems. Until recently, however, the global extent of the coral reef crisis was unknown. Reef Check was developed in 1996 as a volunteer, community-based monitoring protocol designed to measure the health of coral reefs on a global scale. With goals of education, monitoring, and management, Reef Check has activities in over 60 countries and territories. They have not only provided scientific evidence of the global extent of the coral reef crisis, but have provided the first community based steps to alleviate this urgent situation.
Energy Technology Data Exchange (ETDEWEB)
Ambrose, David M.; Wilkening, Jon
2008-12-11
We classify all bifurcations from traveling waves to non-trivial time-periodic solutions of the Benjamin-Ono equation that are predicted by linearization. We use a spectrally accurate numerical continuation method to study several paths of non-trivial solutions beyond the realm of linear theory. These paths are found to either re-connect with a different traveling wave or to blow up. In the latter case, as the bifurcation parameter approaches a critical value, the amplitude of the initial condition grows without bound and the period approaches zero. We propose a conjecture that gives the mapping from one bifurcation to its counterpart on the other side of the path of non-trivial solutions. By experimentation with data fitting, we identify the form of the exact solutions on the path connecting two traveling waves, which represents the Fourier coefficients of the solution as power sums of a finite number of particle positions whose elementary symmetric functions execute simple orbits in the complex plane (circles or epicycles). We then solve a system of algebraic equations to express the unknown constants in the new representation in terms of the mean, a spatial phase, a temporal phase, four integers (enumerating the bifurcation at each end of the path) and one additional bifurcation parameter. We also find examples of interior bifurcations from these paths of already non-trivial solutions, but we do not attempt to analyze their algebraic structure.
Measurement of weak radioactivity
Theodorsson , P
1996-01-01
This book is intended for scientists engaged in the measurement of weak alpha, beta, and gamma active samples; in health physics, environmental control, nuclear geophysics, tracer work, radiocarbon dating etc. It describes the underlying principles of radiation measurement and the detectors used. It also covers the sources of background, analyzes their effect on the detector and discusses economic ways to reduce the background. The most important types of low-level counting systems and the measurement of some of the more important radioisotopes are described here. In cases where more than one type can be used, the selection of the most suitable system is shown.
Yee, H. C.; Sweby, P. K.
1995-01-01
The global asymptotic nonlinear behavior of 11 explicit and implicit time discretizations for four 2 x 2 systems of first-order autonomous nonlinear ordinary differential equations (ODEs) is analyzed. The objectives are to gain a basic understanding of the difference in the dynamics of numerics between the scalars and systems of nonlinear autonomous ODEs and to set a baseline global asymptotic solution behavior of these schemes for practical computations in computational fluid dynamics. We show how 'numerical' basins of attraction can complement the bifurcation diagrams in gaining more detailed global asymptotic behavior of time discretizations for nonlinear differential equations (DEs). We show how in the presence of spurious asymptotes the basins of the true stable steady states can be segmented by the basins of the spurious stable and unstable asymptotes. One major consequence of this phenomenon which is not commonly known is that this spurious behavior can result in a dramatic distortion and, in most cases, a dramatic shrinkage and segmentation of the basin of attraction of the true solution for finite time steps. Such distortion, shrinkage and segmentation of the numerical basins of attraction will occur regardless of the stability of the spurious asymptotes, and will occur for unconditionally stable implicit linear multistep methods. In other words, for the same (common) steady-state solution the associated basin of attraction of the DE might be very different from the discretized counterparts and the numerical basin of attraction can be very different from numerical method to numerical method. The results can be used as an explanation for possible causes of error, and slow convergence and nonconvergence of steady-state numerical solutions when using the time-dependent approach for nonlinear hyperbolic or parabolic PDEs.
Joint and weak measurements on qubit systems
International Nuclear Information System (INIS)
O'Brien, J.L.; Pryde, G.J.; Bartlett, S.D.; Ralph, T.C.; Wiseman, H.M.; White, A.G.
2005-01-01
Full text: Along with the well-known concept of projective measurements, quantum mechanics allows various kinds of generalized measurement operators. Two important examples are: joint measurements on two or more quantum systems that cannot be achieved by local operations (LOCC); and weak measurements that obtain less information about a system than does a projective measurement, but with correspondingly less disturbance. Unlike the result of a strong measurement, the average value of a weak measurement of an observable (its weak value), when followed by projective postselection in a complementary basis, can lie outside the range of eigenvalues. This discrepancy is not observed in analogous classical measurements. Weak values aid the resolution of quantum paradoxes, and can simplify analysis of weakly coupled systems. We use a generalized measurement device to measure the weak value of a photon's polarization in the horizontal/vertical basis (the Stokes operator S1 = |H> weak up to 47, outside the usual range -1 ≤ S1 ≤ 1. Unlike previous observations of weak values, our measurement works by entangling two separate systems, and thus can only be described by quantum theory, not a classical wave theory. Also, we have used a two-qubit joint measurement based on a controlled-NOT gate by which certain twoqubit unentangled states can be more reliably distinguished than by using LOCC. We quantify this using a payoff function, for which the optimal LOCC measurement attains 2/3, and our experimental measurement attains 0.72 ± 0.02, close to the global optimum of 3/4. (author)
HIV/AIDS: global trends, global funds and delivery bottlenecks
Coovadia, Hoosen M; Hadingham, Jacqui
2005-01-01
Globalisation affects all facets of human life, including health and well being. The HIV/AIDS epidemic has highlighted the global nature of human health and welfare and globalisation has given rise to a trend toward finding common solutions to global health challenges. Numerous international funds have been set up in recent times to address global health challenges such as HIV. However, despite increasingly large amounts of funding for health initiatives being made available to poorer regions of the world, HIV infection rates and prevalence continue to increase world wide. As a result, the AIDS epidemic is expanding and intensifying globally. Worst affected are undoubtedly the poorer regions of the world as combinations of poverty, disease, famine, political and economic instability and weak health infrastructure exacerbate the severe and far-reaching impacts of the epidemic. One of the major reasons for the apparent ineffectiveness of global interventions is historical weaknesses in the health systems of underdeveloped countries, which contribute to bottlenecks in the distribution and utilisation of funds. Strengthening these health systems, although a vital component in addressing the global epidemic, must however be accompanied by mitigation of other determinants as well. These are intrinsically complex and include social and environmental factors, sexual behaviour, issues of human rights and biological factors, all of which contribute to HIV transmission, progression and mortality. An equally important factor is ensuring an equitable balance between prevention and treatment programmes in order to holistically address the challenges presented by the epidemic. PMID:16060961
HIV/AIDS: global trends, global funds and delivery bottlenecks
Directory of Open Access Journals (Sweden)
Hadingham Jacqui
2005-08-01
Full Text Available Abstract Globalisation affects all facets of human life, including health and well being. The HIV/AIDS epidemic has highlighted the global nature of human health and welfare and globalisation has given rise to a trend toward finding common solutions to global health challenges. Numerous international funds have been set up in recent times to address global health challenges such as HIV. However, despite increasingly large amounts of funding for health initiatives being made available to poorer regions of the world, HIV infection rates and prevalence continue to increase world wide. As a result, the AIDS epidemic is expanding and intensifying globally. Worst affected are undoubtedly the poorer regions of the world as combinations of poverty, disease, famine, political and economic instability and weak health infrastructure exacerbate the severe and far-reaching impacts of the epidemic. One of the major reasons for the apparent ineffectiveness of global interventions is historical weaknesses in the health systems of underdeveloped countries, which contribute to bottlenecks in the distribution and utilisation of funds. Strengthening these health systems, although a vital component in addressing the global epidemic, must however be accompanied by mitigation of other determinants as well. These are intrinsically complex and include social and environmental factors, sexual behaviour, issues of human rights and biological factors, all of which contribute to HIV transmission, progression and mortality. An equally important factor is ensuring an equitable balance between prevention and treatment programmes in order to holistically address the challenges presented by the epidemic.
A coupled chemotaxis-fluid model: Global existence
Liu, Jian-Guo
2011-09-01
We consider a model arising from biology, consisting of chemotaxis equations coupled to viscous incompressible fluid equations through transport and external forcing. Global existence of solutions to the Cauchy problem is investigated under certain conditions. Precisely, for the chemotaxis-Navier- Stokes system in two space dimensions, we obtain global existence for large data. In three space dimensions, we prove global existence of weak solutions for the chemotaxis-Stokes system with nonlinear diffusion for the cell density.© 2011 Elsevier Masson SAS. All rights reserved.
Milton, Graeme W.; Camar-Eddine, Mohamed
2018-05-01
For a composite containing one isotropic elastic material, with positive Lame moduli, and void, with the elastic material occupying a prescribed volume fraction f, and with the composite being subject to an average stress, σ0 , Gibiansky, Cherkaev, and Allaire provided a sharp lower bound Wf(σ0) on the minimum compliance energy σ0 :ɛ0 , in which ɛ0 is the average strain. Here we show these bounds also provide sharp bounds on the possible (σ0 ,ɛ0) -pairs that can coexist in such composites, and thus solve the weak G-closure problem for 3d-printed materials. The materials we use to achieve the extremal (σ0 ,ɛ0) -pairs are denoted as near optimal pentamodes. We also consider two-phase composites containing this isotropic elasticity material and a rigid phase with the elastic material occupying a prescribed volume fraction f, and with the composite being subject to an average strain, ɛ0. For such composites, Allaire and Kohn provided a sharp lower bound W˜f(ɛ0) on the minimum elastic energy σ0 :ɛ0 . We show that these bounds also provide sharp bounds on the possible (σ0 ,ɛ0) -pairs that can coexist in such composites of the elastic and rigid phases, and thus solve the weak G-closure problem in this case too. The materials we use to achieve these extremal (σ0 ,ɛ0) -pairs are denoted as near optimal unimodes.
Tewksbury, J.; Gaffney, O.; Young, D.
2016-12-01
People are more willing to accept and act on the science surrounding global environmental change when they can see themselves in that change - or when they can understand how global processes like climate change impact their lives in concrete and intimate ways. The digital revolution presents unique opportunities to make those sorts of connections. We will explore how new technologies can help to immerse users in the challenges of global sustainability and deepen their sense of personal involvement. We will draw on case studies from the Future Earth Media Lab, a communications and research initiative that was formed by Future Earth, the International Council for Science (ICSU) and Globaïa in 2015. The Media Lab was set up to bring together partners from science, technology, art and design to co-create products and experiences that can change the way we communicate the challenges of the world's most intractable problems, with the potential to shift mindsets and behaviours. We are at the very beginning of this 10-year project to explore how advances in virtual reality, augmented reality, data visualization and artificial intelligence will reshape how non-scientific audiences engage with science. The session will focus on results of the most recent projects launched in 2016: a hackathon series with the Iris.AI artificial intelligence project to test the limits of AI for searches based on framed research questions; a global hackathon series around using virtual reality to communicate global change challenges and an immersive space co-created with data visualization experts at the UN's biggest conference on sustainable urbanization at Quito, Ecuador.
Weakly relativistic plasma expansion
Energy Technology Data Exchange (ETDEWEB)
Fermous, Rachid, E-mail: rfermous@usthb.dz; Djebli, Mourad, E-mail: mdjebli@usthb.dz [Theoretical Physics Laboratory, Faculty of Physics, USTHB, B.P. 32 Bab-Ezzouar, 16079 Algiers (Algeria)
2015-04-15
Plasma expansion is an important physical process that takes place in laser interactions with solid targets. Within a self-similar model for the hydrodynamical multi-fluid equations, we investigated the expansion of both dense and under-dense plasmas. The weakly relativistic electrons are produced by ultra-intense laser pulses, while ions are supposed to be in a non-relativistic regime. Numerical investigations have shown that relativistic effects are important for under-dense plasma and are characterized by a finite ion front velocity. Dense plasma expansion is found to be governed mainly by quantum contributions in the fluid equations that originate from the degenerate pressure in addition to the nonlinear contributions from exchange and correlation potentials. The quantum degeneracy parameter profile provides clues to set the limit between under-dense and dense relativistic plasma expansions at a given density and temperature.
Lorenzi, Nancy; De Moor, Georges; Bloomrosen, Meryl; Stroetmann, Karl
2011-01-01
In 2010 the ARGOS project was funded by the EC (DG RELEX) to contribute to the establishement of a "Transatlantic Observatory for meeting Global Health Policy Challenges through Information and Communication Technology-enabled solutions" to develop and promote common methods for responding to global eHealth challenges in the EU and the US. The European Institute for Health Records (EuroRec) was coordinating the project. The vision is that the Transatlantic Observatory will act as an international platform for dialogue and collaboration on health policy issues and will 1. build international consensus about how to improve the access, efficiency and quality of health services through ICT, 2. promote the importance of interoperability in eHealth, 3. help to define approaches to ensure that health data are easily available where it is needed, 4. identify optimal development paths.
Secure Authentication from a Weak Key, Without Leaking Information
N.J. Bouman (Niek); S. Fehr (Serge); K.G. Paterson (Kerry)
2011-01-01
htmlabstractWe study the problem of authentication based on a weak key in the information-theoretic setting. A key is weak if its min-entropy is an arbitrary small fraction of its bit length. This problem has recently received considerable attention, with different solutions optimizing different
Samanta, Saumik; Dalai, Tarun K.
2018-05-01
The Ganga River System is a major contributor to the global sediment and water discharge to the oceans. The estuary of Ganga (Hooghly) River in India is under increasing influence of anthropogenic contributions via discharge of the industrial and urban effluents. Here we document, based on the investigation of water and suspended sediment samples collected during six periods over two years, that there is extensive production of heavy metals (Co, Ni and Cu) in the estuary such that the annual dissolved fluxes of metals from the Hooghly River are enhanced by up to 230-1770%. Furthermore, the estuarine dissolved metal fluxes, when normalized with water fluxes, are the highest among estuaries of the major rivers in the world. Our simultaneous data on the dissolved, suspended particulate and exchangeable phases allow us to identify the ion-exchange process (coupled adsorption and desorption) as the dominant contributor to the generation of heavy metals in the middle and lower estuary where the estimated anthropogenic contribution is negligible. The estimated contributions from the groundwater are also insufficient to explain the measured metal concentrations in the estuary. A strong positive correlation that is observed between the dissolved heavy metal fluxes and the suspended particulate matter (SPM) fluxes, after normalizing them with the water fluxes, for estuaries of the major global rivers imply that the solute-particle interaction is a globally significant process in the estuarine production of metals. Based on this correlation that is observed for major estuaries around the world, we demonstrate that the South Asian Rivers which supply only ∼9% of the global river water discharge but carry elevated SPM load, contribute a far more significant proportion (∼40 ± 2% Ni and 15 ± 1% Cu) to the global supply of the dissolved metals from the rivers.
Directory of Open Access Journals (Sweden)
Gregory Giuliani
2017-12-01
Considering that climate data is part of the broader Earth observation and geospatial data domain, the aim of this paper is to review the state-of-the-art geospatial technologies that can support the delivery of efficient and effective climate services, and enhancing the value chain of climate data in support of the objectives of the Global Framework for Climate Services. The major benefit of spatially-enabling climate services is that it brings interoperability along the entire climate data value chain. It facilitates storing, visualizing, accessing, processing/analyzing, and integrating climate data and information and enables users to create value-added products and services.
Scipal, K.; Holmes, T.; de Jeu, R.; Naeimi, V.; Wagner, W.
2008-12-01
In the last few years, research made significant progress towards operational soil moisture remote sensing which lead to the availability of several global data sets. For an optimal use of these data, an accurate estimation of the error structure is an important condition. To solve for the validation problem we introduce the triple collocation error estimation technique. The triple collocation technique is a powerful tool to estimate the root mean square error while simultaneously solving for systematic differences in the climatologies of a set of three independent data sources. We evaluate the method by applying it to a passive microwave (TRMM radiometer) derived, an active microwave (ERS-2 scatterometer) derived and a modeled (ERA-Interim reanalysis) soil moisture data sets. The results suggest that the method provides realistic error estimates.
Perera, Frederica
2017-12-23
Fossil-fuel combustion by-products are the world's most significant threat to children's health and future and are major contributors to global inequality and environmental injustice. The emissions include a myriad of toxic air pollutants and carbon dioxide (CO₂), which is the most important human-produced climate-altering greenhouse gas. Synergies between air pollution and climate change can magnify the harm to children. Impacts include impairment of cognitive and behavioral development, respiratory illness, and other chronic diseases-all of which may be "seeded" in utero and affect health and functioning immediately and over the life course. By impairing children's health, ability to learn, and potential to contribute to society, pollution and climate change cause children to become less resilient and the communities they live in to become less equitable. The developing fetus and young child are disproportionately affected by these exposures because of their immature defense mechanisms and rapid development, especially those in low- and middle-income countries where poverty and lack of resources compound the effects. No country is spared, however: even high-income countries, especially low-income communities and communities of color within them, are experiencing impacts of fossil fuel-related pollution, climate change and resultant widening inequality and environmental injustice. Global pediatric health is at a tipping point, with catastrophic consequences in the absence of bold action. Fortunately, technologies and interventions are at hand to reduce and prevent pollution and climate change, with large economic benefits documented or predicted. All cultures and communities share a concern for the health and well-being of present and future children: this shared value provides a politically powerful lever for action. The purpose of this commentary is to briefly review the data on the health impacts of fossil-fuel pollution, highlighting the neurodevelopmental
Di Pietro, Daniele A.; Marche, Fabien
2018-02-01
In this paper, we further investigate the use of a fully discontinuous Finite Element discrete formulation for the study of shallow water free surface flows in the fully nonlinear and weakly dispersive flow regime. We consider a decoupling strategy in which we approximate the solutions of the classical shallow water equations supplemented with a source term globally accounting for the non-hydrostatic effects. This source term can be computed through the resolution of elliptic second-order linear sub-problems, which only involve second order partial derivatives in space. We then introduce an associated Symmetric Weighted Internal Penalty discrete bilinear form, allowing to deal with the discontinuous nature of the elliptic problem's coefficients in a stable and consistent way. Similar discrete formulations are also introduced for several recent optimized fully nonlinear and weakly dispersive models. These formulations are validated again several benchmarks involving h-convergence, p-convergence and comparisons with experimental data, showing optimal convergence properties.
Global existence and blowup for free boundary problems of coupled reaction-diffusion systems
Directory of Open Access Journals (Sweden)
Jianping Sun
2014-05-01
Full Text Available This article concerns a free boundary problem for a reaction-diffusion system modeling the cooperative interaction of two diffusion biological species in one space dimension. First we show the existence and uniqueness of a local classical solution, then we study the asymptotic behavior of the free boundary problem. Our results show that the free boundary problem admits a global solution if the inter-specific competitions are strong, while, if the inter-specific competitions are weak, there exist the blowup solution and a global fast solution.
Zilberberg, Oded; Romito, Alessandro; Gefen, Yuval
2013-01-01
Weak value (WV) is a quantum mechanical measurement protocol, proposed by Aharonov, Albert, and Vaidman. It consists of a weak measurement, which is weighed in, conditional on the outcome of a later, strong measurement. Here we define another two-step measurement protocol, null weak value (NVW), and point out its advantages as compared to WV. We present two alternative derivations of NWVs and compare them to the corresponding derivations of WVs.
Weak Measurement and Quantum Correlation
Indian Academy of Sciences (India)
Arun Kumar Pati
The concept of the weak measurements, for the first time, was introduced by Aharonov et al.1. Quantum state is preselected in |ψi〉 and allowed to interact weakly with apparatus. Measurement strength can be tuned and for “small g(t)” it is called 'weak measurement'. With postselection in |ψf 〉, apparatus state is shifted by an ...
Weak openness and almost openness
Directory of Open Access Journals (Sweden)
David A. Rose
1984-01-01
Full Text Available Weak openness and almost openness for arbitrary functions between topological spaces are defined as duals to the weak continuity of Levine and the almost continuity of Husain respectively. Independence of these two openness conditions is noted and comparison is made between these and the almost openness of Singal and Singal. Some results dual to those known for weak continuity and almost continuity are obtained. Nearly almost openness is defined and used to obtain an improved link from weak continuity to almost continuity.
Weak Weak Lensing : How Accurately Can Small Shears be Measured?
Kuijken, K.
2006-01-01
Abstract: Now that weak lensing signals on the order of a percent are actively being searched for (cosmic shear, galaxy-galaxy lensing, large radii in clusters...) it is important to investigate how accurately weak shears can be determined. Many systematic effects are present, and need to be
Reducing Weak to Strong Bisimilarity in CCP
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Andrés Aristizábal
2012-12-01
Full Text Available Concurrent constraint programming (ccp is a well-established model for concurrency that singles out the fundamental aspects of asynchronous systems whose agents (or processes evolve by posting and querying (partial information in a global medium. Bisimilarity is a standard behavioural equivalence in concurrency theory. However, only recently a well-behaved notion of bisimilarity for ccp, and a ccp partition refinement algorithm for deciding the strong version of this equivalence have been proposed. Weak bisimiliarity is a central behavioural equivalence in process calculi and it is obtained from the strong case by taking into account only the actions that are observable in the system. Typically, the standard partition refinement can also be used for deciding weak bisimilarity simply by using Milner's reduction from weak to strong bisimilarity; a technique referred to as saturation. In this paper we demonstrate that, because of its involved labeled transitions, the above-mentioned saturation technique does not work for ccp. We give an alternative reduction from weak ccp bisimilarity to the strong one that allows us to use the ccp partition refinement algorithm for deciding this equivalence.
Modelling, Measuring and Compensating Color Weak Vision.
Oshima, Satoshi; Mochizuki, Rika; Lenz, Reiner; Chao, Jinhui
2016-03-08
We use methods from Riemann geometry to investigate transformations between the color spaces of color-normal and color weak observers. The two main applications are the simulation of the perception of a color weak observer for a color normal observer and the compensation of color images in a way that a color weak observer has approximately the same perception as a color normal observer. The metrics in the color spaces of interest are characterized with the help of ellipsoids defined by the just-noticable-differences between color which are measured with the help of color-matching experiments. The constructed mappings are isometries of Riemann spaces that preserve the perceived color-differences for both observers. Among the two approaches to build such an isometry, we introduce normal coordinates in Riemann spaces as a tool to construct a global color-weak compensation map. Compared to previously used methods this method is free from approximation errors due to local linearizations and it avoids the problem of shifting locations of the origin of the local coordinate system. We analyse the variations of the Riemann metrics for different observers obtained from new color matching experiments and describe three variations of the basic method. The performance of the methods is evaluated with the help of semantic differential (SD) tests.
Jarrar, Mu’taman; Rahman, Hamzah Abdul; Don, Mohammad Sobri
2016-01-01
Background and Objective: Demand for health care service has significantly increased, while the quality of healthcare and patient safety has become national and international priorities. This paper aims to identify the gaps and the current initiatives for optimizing the quality of care and patient safety in Malaysia. Design: Review of the current literature. Highly cited articles were used as the basis to retrieve and review the current initiatives for optimizing the quality of care and patient safety. The country health plan of Ministry of Health (MOH) Malaysia and the MOH Malaysia Annual Reports were reviewed. Results: The MOH has set four strategies for optimizing quality and sustaining quality of life. The 10th Malaysia Health Plan promotes the theme “1 Care for 1 Malaysia” in order to sustain the quality of care. Despite of these efforts, the total number of complaints received by the medico-legal section of the MOH Malaysia is increasing. The current global initiatives indicted that quality performance generally belong to three main categories: patient; staffing; and working environment related factors. Conclusions: There is no single intervention for optimizing quality of care to maintain patient safety. Multidimensional efforts and interventions are recommended in order to optimize the quality of care and patient safety in Malaysia. PMID:26755459
Friedbichler, Michael; Friedbichler, Ingrid; Türp, Jens Christoph
2008-01-01
In a world which is shrinking at a dramatic pace the need for international communication is constantly rising. In this global setting, the English language has increasingly become the "lingua franca" in which most scientific exchange takes place among professionals worldwide. The present paper investigates the impact of the all-pervasive role of English on the language of medicine and dentistry in the German-speaking countries as well as recent efforts to overcome some of the major obstacles associated with international communication. Possible approaches how non-anglophone dental communities can participate in scientific communication worldwide without starving their own language are assessed. The authors demonstrate that there is no alternative to bilingual competence in professional contexts and emphasize the need for strategies to promote bilingualism in scientific communication. Integrating bilingual language training at dental schools and in continuing education seems indispensable. A survey of bilingual models at medical and dental schools in other countries reveals significant deficits at German-speaking universities in this field. Promising new bilingual approaches in dental journals, lexicography, and other terminology resources are discussed, particularly the so-called KWiC-Web concept, a new semi-bilingual language guide to dental English, which helps German-speaking dental professionals to acquire and master the relevant language skills.
Jarrar, Mu'taman; Abdul Rahman, Hamzah; Don, Mohammad Sobri
2015-10-20
Demand for health care service has significantly increased, while the quality of healthcare and patient safety has become national and international priorities. This paper aims to identify the gaps and the current initiatives for optimizing the quality of care and patient safety in Malaysia. Review of the current literature. Highly cited articles were used as the basis to retrieve and review the current initiatives for optimizing the quality of care and patient safety. The country health plan of Ministry of Health (MOH) Malaysia and the MOH Malaysia Annual Reports were reviewed. The MOH has set four strategies for optimizing quality and sustaining quality of life. The 10th Malaysia Health Plan promotes the theme "1 Care for 1 Malaysia" in order to sustain the quality of care. Despite of these efforts, the total number of complaints received by the medico-legal section of the MOH Malaysia is increasing. The current global initiatives indicted that quality performance generally belong to three main categories: patient; staffing; and working environment related factors. There is no single intervention for optimizing quality of care to maintain patient safety. Multidimensional efforts and interventions are recommended in order to optimize the quality of care and patient safety in Malaysia.
Yang, Qixiang; Yang, Haibo
2018-04-01
For fractional Navier-Stokes equations and critical initial spaces X, one used to establish the well-posedness in the solution space which is contained in C (R+ , X). In this paper, for heat flow, we apply parameter Meyer wavelets to introduce Y spaces Y m , β where Y m , β is not contained in C (R+, B˙∞ 1 - 2 β , ∞). Consequently, for 1/2 Navier-Stokes equations with small initial data in all the critical oscillation spaces. The critical oscillation spaces may be any Besov-Morrey spaces (B˙p,q γ1 ,γ2 (Rn)) n or any Triebel-Lizorkin-Morrey spaces (F˙p,q γ1 ,γ2 (Rn)) n where 1 ≤ p , q ≤ ∞ , 0 ≤γ2 ≤ n/p, γ1 -γ2 = 1 - 2 β. These critical spaces include many known spaces. For example, Besov spaces, Sobolev spaces, Bloch spaces, Q-spaces, Morrey spaces and Triebel-Lizorkin spaces etc.
Synchronization of weakly coupled canard oscillators
Köksal Ersöz, Elif; Desroches, Mathieu; Krupa, Martin
2017-06-01
Synchronization has been studied extensively in the context of weakly coupled oscillators using the so-called phase response curve (PRC) which measures how a change of the phase of an oscillator is affected by a small perturbation. This approach was based upon the work of Malkin, and it has been extended to relaxation oscillators. Namely, synchronization conditions were established under the weak coupling assumption, leading to a criterion for the existence of synchronous solutions of weakly coupled relaxation oscillators. Previous analysis relies on the fact that the slow nullcline does not intersect the fast nullcline near one of its fold points, where canard solutions can arise. In the present study we use numerical continuation techniques to solve the adjoint equations and we show that synchronization properties of canard cycles are different than those of classical relaxation cycles. In particular, we highlight a new special role of the maximal canard in separating two distinct synchronization regimes: the Hopf regime and the relaxation regime. Phase plane analysis of slow-fast oscillators undergoing a canard explosion provides an explanation for this change of synchronization properties across the maximal canard.
Weak Approximation of SDEs by Discrete-Time Processes
Directory of Open Access Journals (Sweden)
Henryk Zähle
2008-01-01
Full Text Available We consider the martingale problem related to the solution of an SDE on the line. It is shown that the solution of this martingale problem can be approximated by solutions of the corresponding time-discrete martingale problems under some conditions. This criterion is especially expedient for establishing the convergence of population processes to SDEs. We also show that the criterion yields a weak Euler scheme approximation of SDEs under fairly weak assumptions on the driving force of the approximating processes.
Electromagnetic current in weak interactions
International Nuclear Information System (INIS)
Ma, E.
1983-01-01
In gauge models which unify weak and electromagnetic interactions, the weak neutral-current interaction also involves the electromagnetic current. The exact nature of such a component can be explored using e + e - experimental data. In recent years, the existence of a new component of the weak interaction has become firmly established, i.e., the neutral-current interaction. As such, it competes with the electromagnetic interaction whenever the particles involved are also charged, but at a very much lower rate because its effective strength is so small. Hence neutrino processes are best for the detection of the neutral-current interaction. However, in any gauge model which unifies weak and electromagnetic interactions, the weak neutral-current interaction also involves the electromagnetic current
The Weak Gravity Conjecture in three dimensions
Energy Technology Data Exchange (ETDEWEB)
Montero, Miguel [Departamento de Física Teórica, Facultad de Ciencias,Universidad Autónoma de Madrid,Calle Francisco Tomás y Valiente 7, 28049 Madrid (Spain); Instituto de Física Teórica IFT-UAM/CSIC, Campus de Cantoblanco,C/ Nicolás Cabrera 13-15, 28049 Madrid (Spain); Shiu, Gary; Soler, Pablo [Department of Physics, University of Wisconsin-Madison,1150 University Ave, Madison, WI 53706 (United States); Department of Physics & Institute for Advanced Study,Hong Kong University of Science and Technology,Lo Ka Chung Building, Lee Shau Kee Campus, Clear Water Bay (Hong Kong)
2016-10-28
We study weakly coupled U(1) theories in AdS{sub 3}, their associated charged BTZ solutions, and their charged spectra. We find that modular invariance of the holographic dual two-dimensional CFT and compactness of the gauge group together imply the existence of charged operators with conformal dimension significantly below the black hole threshold. We regard this as a form of the Weak Gravity Conjecture (WGC) in three dimensions. We also explore the constraints posed by modular invariance on a particular discrete ℤ{sub N} symmetry which arises in our discussion. In this case, modular invariance does not guarantee the existence of light ℤ{sub N}-charged states. We also highlight the differences between our discussion and the usual heuristic arguments for the WGC based on black hole remnants.
Anand, Sonia S; Hawkes, Corinna; de Souza, Russell J; Mente, Andrew; Dehghan, Mahshid; Nugent, Rachel; Zulyniak, Michael A; Weis, Tony; Bernstein, Adam M; Krauss, Ronald M; Kromhout, Daan; Jenkins, David J A; Malik, Vasanti; Martinez-Gonzalez, Miguel A; Mozaffarian, Dariush; Yusuf, Salim; Willett, Walter C; Popkin, Barry M
2015-10-06
Major scholars in the field, on the basis of a 3-day consensus, created an in-depth review of current knowledge on the role of diet in cardiovascular disease (CVD), the changing global food system and global dietary patterns, and potential policy solutions. Evidence from different countries and age/race/ethnicity/socioeconomic groups suggesting the health effects studies of foods, macronutrients, and dietary patterns on CVD appear to be far more consistent though regional knowledge gaps is highlighted. Large gaps in knowledge about the association of macronutrients to CVD in low- and middle-income countries particularly linked with dietary patterns are reviewed. Our understanding of foods and macronutrients in relationship to CVD is broadly clear; however, major gaps exist both in dietary pattern research and ways to change diets and food systems. On the basis of the current evidence, the traditional Mediterranean-type diet, including plant foods and emphasis on plant protein sources provides a well-tested healthy dietary pattern to reduce CVD. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Global dynamics of a reaction-diffusion system
Directory of Open Access Journals (Sweden)
Yuncheng You
2011-02-01
Full Text Available In this work the existence of a global attractor for the semiflow of weak solutions of a two-cell Brusselator system is proved. The method of grouping estimation is exploited to deal with the challenge in proving the absorbing property and the asymptotic compactness of this type of coupled reaction-diffusion systems with cubic autocatalytic nonlinearity and linear coupling. It is proved that the Hausdorff dimension and the fractal dimension of the global attractor are finite. Moreover, the existence of an exponential attractor for this solution semiflow is shown.
Hartman effect and weak measurements that are not really weak
International Nuclear Information System (INIS)
Sokolovski, D.; Akhmatskaya, E.
2011-01-01
We show that in wave packet tunneling, localization of the transmitted particle amounts to a quantum measurement of the delay it experiences in the barrier. With no external degree of freedom involved, the envelope of the wave packet plays the role of the initial pointer state. Under tunneling conditions such ''self-measurement'' is necessarily weak, and the Hartman effect just reflects the general tendency of weak values to diverge, as postselection in the final state becomes improbable. We also demonstrate that it is a good precision, or a 'not really weak' quantum measurement: no matter how wide the barrier d, it is possible to transmit a wave packet with a width σ small compared to the observed advancement. As is the case with all weak measurements, the probability of transmission rapidly decreases with the ratio σ/d.
Conformational transitions of a weak polyampholyte
Nair, Arun Kumar Narayanan
2014-10-07
Using grand canonical Monte Carlo simulations of a flexible polyelectrolyte where the charges are in contact with a reservoir of constant chemical potential given by the solution pH, we study the behavior of weak polyelectrolytes in poor and good solvent conditions for polymer backbone. We address the titration behavior and conformational properties of a flexible diblock polyampholyte chain formed of two oppositely charged weak polyelectrolyte blocks, each containing equal number of identical monomers. The change of solution pH induces charge asymmetry in a diblock polyampholyte. For diblock polyampholyte chains in poor solvents, we demonstrate that a discontinuous transition between extended (tadpole) and collapsed (globular) conformational states is attainable by varying the solution pH. The double-minima structure in the probability distribution of the free energy provides direct evidence for the first-order like nature of this transition. At the isoelectric point electrostatically driven coil-globule transition of diblock polyampholytes in good solvents is found to consist of different regimes identified with increasing electrostatic interaction strength. At pH values above or below the isoelectric point diblock chains are found to have polyelectrolyte-like behavior due to repulsion between uncompensated charges along the chain.
International Nuclear Information System (INIS)
Androic, D.; Armstrong, D. S.; Asaturyan, A.; Averett, T.; Balewski, J.; Beaufait, J.; Beminiwattha, R. S.; Benesch, J.; Benmokhtar, F.; Birchall, J.; Carlini, R. D.; Cornejo, J. C.; Covrig, S.; Dalton, M. M.; Davis, C. A.; Deconinck, W.; Diefenbach, J.; Dow, K.; Dowd, J. F.; Dunne, J. A.
2013-01-01
In May 2012, the Q p Weak collaboration completed a two year measurement program to determine the weak charge of the proton Q W p = ( 1 - 4sin 2 θ W ) at the Thomas Jefferson National Accelerator Facility (TJNAF). The experiment was designed to produce a 4.0 % measurement of the weak charge, via a 2.5 % measurement of the parity violating asymmetry in the number of elastically scattered 1.165 GeV electrons from protons, at forward angles. At the proposed precision, the experiment would produce a 0.3 % measurement of the weak mixing angle at a momentum transfer of Q 2 = 0.026 GeV 2 , making it the most precise stand alone measurement of the weak mixing angle at low momentum transfer. In combination with other parity measurements, Q p Weak will also provide a high precision determination of the weak charges of the up and down quarks. At the proposed precision, a significant deviation from the Standard Model prediction could be a signal of new physics at mass scales up to ≃ 6 TeV, whereas agreement would place new and significant constraints on possible Standard Model extensions at mass scales up to ≃ 2 TeV. This paper provides an overview of the physics and the experiment, as well as a brief look at some preliminary diagnostic and analysis data.
Experimental investigations of weak definite and weak indefinite noun phrases.
Klein, Natalie M; Gegg-Harrison, Whitney M; Carlson, Greg N; Tanenhaus, Michael K
2013-08-01
Definite noun phrases typically refer to entities that are uniquely identifiable in the speaker and addressee's common ground. Some definite noun phrases (e.g., the hospital in Mary had to go the hospital and John did too) seem to violate this uniqueness constraint. We report six experiments that were motivated by the hypothesis that these "weak definite" interpretations arise in "incorporated" constructions. Experiments 1-3 compared nouns that seem to allow for a weak definite interpretation (e.g., hospital, bank, bus, radio) with those that do not (e.g., farm, concert, car, book). Experiments 1 and 2 used an instruction-following task and picture-judgment task, respectively, to demonstrate that a weak definite need not uniquely refer. In Experiment 3 participants imagined scenarios described by sentences such as The Federal Express driver had to go to the hospital/farm. Scenarios following weak definite noun phrases were more likely to include conventional activities associated with the object, whereas following regular nouns, participants were more likely to imagine scenarios that included typical activities associated with the subject; similar effects were observed with weak indefinites. Experiment 4 found that object-related activities were reduced when the same subject and object were used with a verb that does not license weak definite interpretations. In Experiment 5, a science fiction story introduced an artificial lexicon for novel concepts. Novel nouns that shared conceptual properties with English weak definite nouns were more likely to allow weak reference in a judgment task. Experiment 6 demonstrated that familiarity for definite articles and anti-familiarity for indefinite articles applies to the activity associated with the noun, consistent with predictions made by the incorporation analysis. Copyright © 2013 Elsevier B.V. All rights reserved.
Resisting Weakness of the Will.
Levy, Neil
2011-01-01
I develop an account of weakness of the will that is driven by experimental evidence from cognitive and social psychology. I will argue that this account demonstrates that there is no such thing as weakness of the will: no psychological kind corresponds to it. Instead, weakness of the will ought to be understood as depletion of System II resources. Neither the explanatory purposes of psychology nor our practical purposes as agents are well-served by retaining the concept. I therefore suggest that we ought to jettison it, in favour of the vocabulary and concepts of cognitive psychology.
Magnetic braking in weakly ionized media
Konigl, Arieh
1987-01-01
The combined magnetic braking-ambipolar diffusion problem in weakly ionized, rigidly rotating disks is studied. An analytical solution is presented for a disk whose angular velocity and magnetic yield vectors are aligned with the symmetry axis, illustrating the effects of the relative azimuthal drift of neutrals and ions. The effects of radial drift are added, commenting on the ratio of the characteristic ambipolar diffusion and magnetic braking time scales in high-mass and low-mass disks. A numerical calculation is used to show the combined action of these two processes.
Superconductor in a weak static gravitational field
Energy Technology Data Exchange (ETDEWEB)
Ummarino, Giovanni Alberto [Dipartimento DISAT, Politecnico di Torino, Turin (Italy); National Research Nuclear University MEPhI-Moscow Engineering Physics Institute, Moscow (Russian Federation); Gallerati, Antonio [Dipartimento DISAT, Politecnico di Torino, Turin (Italy)
2017-08-15
We provide the detailed calculation of a general form for Maxwell and London equations that takes into account gravitational corrections in linear approximation. We determine the possible alteration of a static gravitational field in a superconductor making use of the time-dependent Ginzburg-Landau equations, providing also an analytic solution in the weak field condition. Finally, we compare the behavior of a high-T{sub c} superconductor with a classical low-T{sub c} superconductor, analyzing the values of the parameters that can enhance the reduction of the gravitational field. (orig.)
Weakly infinite-dimensional spaces
International Nuclear Information System (INIS)
Fedorchuk, Vitalii V
2007-01-01
In this survey article two new classes of spaces are considered: m-C-spaces and w-m-C-spaces, m=2,3,...,∞. They are intermediate between the class of weakly infinite-dimensional spaces in the Alexandroff sense and the class of C-spaces. The classes of 2-C-spaces and w-2-C-spaces coincide with the class of weakly infinite-dimensional spaces, while the compact ∞-C-spaces are exactly the C-compact spaces of Haver. The main results of the theory of weakly infinite-dimensional spaces, including classification via transfinite Lebesgue dimensions and Luzin-Sierpinsky indices, extend to these new classes of spaces. Weak m-C-spaces are characterised by means of essential maps to Henderson's m-compacta. The existence of hereditarily m-strongly infinite-dimensional spaces is proved.
International Nuclear Information System (INIS)
Franklin, G.B.
1986-01-01
Hypernuclei whose ground states are stable against strong decay are used to study two-baryon weak interactions. A review of th existing experimental data, including recent results from the AGS on /sub Λ/ 12 C and /sub Λ/ 11 B, shows that the lifetimes and branching ratios can be used to test the effective weak Hamiltonians used in the rate calculations. 10 refs., 4 figs
Weakly compact operators and interpolation
Maligranda, Lech
1992-01-01
The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. In this survey, we have collected and ordered some of this (partly very new) knowledge. We have also included some comments, remarks and examples. The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. I...
Weak Deeply Virtual Compton Scattering
Energy Technology Data Exchange (ETDEWEB)
Ales Psaker; Wolodymyr Melnitchouk; Anatoly Radyushkin
2007-03-01
We extend the analysis of the deeply virtual Compton scattering process to the weak interaction sector in the generalized Bjorken limit. The virtual Compton scattering amplitudes for the weak neutral and charged currents are calculated at the leading twist within the framework of the nonlocal light-cone expansion via coordinate space QCD string operators. Using a simple model, we estimate cross sections for neutrino scattering off the nucleon, relevant for future high intensity neutrino beam facilities.
Weak interactions of elementary particles
Okun, Lev Borisovich
1965-01-01
International Series of Monographs in Natural Philosophy, Volume 5: Weak Interaction of Elementary Particles focuses on the composition, properties, and reactions of elementary particles and high energies. The book first discusses elementary particles. Concerns include isotopic invariance in the Sakata model; conservation of fundamental particles; scheme of isomultiplets in the Sakata model; universal, unitary-symmetric strong interaction; and universal weak interaction. The text also focuses on spinors, amplitudes, and currents. Wave function, calculation of traces, five bilinear covariants,
Acute muscular weakness in children
Directory of Open Access Journals (Sweden)
Ricardo Pablo Javier Erazo Torricelli
Full Text Available ABSTRACT Acute muscle weakness in children is a pediatric emergency. During the diagnostic approach, it is crucial to obtain a detailed case history, including: onset of weakness, history of associated febrile states, ingestion of toxic substances/toxins, immunizations, and family history. Neurological examination must be meticulous as well. In this review, we describe the most common diseases related to acute muscle weakness, grouped into the site of origin (from the upper motor neuron to the motor unit. Early detection of hyperCKemia may lead to a myositis diagnosis, and hypokalemia points to the diagnosis of periodic paralysis. Ophthalmoparesis, ptosis and bulbar signs are suggestive of myasthenia gravis or botulism. Distal weakness and hyporeflexia are clinical features of Guillain-Barré syndrome, the most frequent cause of acute muscle weakness. If all studies are normal, a psychogenic cause should be considered. Finding the etiology of acute muscle weakness is essential to execute treatment in a timely manner, improving the prognosis of affected children.
Determination of light yield from weak scintillations
International Nuclear Information System (INIS)
Mandzhukov, I.G.; Mandzhukova, B.V.
1987-01-01
Simulation of amplitude distribution of weak scintillation pulses by Puasson distribution is suggestd, if average number of photoelectrons collected on the first dinode of the photomultiplier is of the order of 1. The method permits to determine scintillation yield even in those cases, when the photomultiplier does not have a maximum in monoelectron pulse distribution. Scintillation yields of some aqueous solutions of sodium salicylate and aromatic solvents (benzene, toluene, xylol) at inner α-particle irradiation are determined. It is observed from the given results that efficiency of 239 Pu α-particle detection for aqueous solutions of sodium salicylate with 10% concentration is rather high; it makes up 0.94. They may appear useful for applied problems, paticularly, for measuring α-radiation
District energy a global solution
Energy Technology Data Exchange (ETDEWEB)
Damecour, R.; Andersson, B. [Kattner/FVB District Energy Inc., Toronto, ON (Canada)
1999-08-01
An overview of the development of district energy systems throughout the world is provided. Significant district energy data is provided for Canada, the United States, East Asia, Korea, Japan, China, Eastern Europe and Russia, Estonia, and Sweden. The overall conclusion is that district energy systems are here to stay and have a good chance of succeeding provided that the concept has the support of business, municipalities and national governments. The 40 years old district heating system in Vasteras, Sweden, the oldest and most successful district energy system in the world, was highlighted.
Cosmology with weak lensing surveys
International Nuclear Information System (INIS)
Munshi, Dipak; Valageas, Patrick; Waerbeke, Ludovic van; Heavens, Alan
2008-01-01
Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are directly related to the distribution of matter and to the geometry and dynamics of the Universe. As a consequence, weak gravitational lensing offers unique possibilities for probing the Dark Matter and Dark Energy in the Universe. In this review, we summarise the theoretical and observational state of the subject, focussing on the statistical aspects of weak lensing, and consider the prospects for weak lensing surveys in the future. Weak gravitational lensing surveys are complementary to both galaxy surveys and cosmic microwave background (CMB) observations as they probe the unbiased non-linear matter power spectrum at modest redshifts. Most of the cosmological parameters are accurately estimated from CMB and large-scale galaxy surveys, so the focus of attention is shifting to understanding the nature of Dark Matter and Dark Energy. On the theoretical side, recent advances in the use of 3D information of the sources from photometric redshifts promise greater statistical power, and these are further enhanced by the use of statistics beyond two-point quantities such as the power spectrum. The use of 3D information also alleviates difficulties arising from physical effects such as the intrinsic alignment of galaxies, which can mimic weak lensing to some extent. On the observational side, in the next few years weak lensing surveys such as CFHTLS, VST-KIDS and Pan-STARRS, and the planned Dark Energy Survey, will provide the first weak lensing surveys covering very large sky areas and depth. In the long run even more ambitious programmes such as DUNE, the Supernova Anisotropy Probe (SNAP) and Large-aperture Synoptic Survey Telescope (LSST) are planned. Weak lensing of diffuse components such as the CMB and 21 cm emission can also
Existence and regularity of weak solutions for singular elliptic problems
Directory of Open Access Journals (Sweden)
Brahim Bougherara
2015-11-01
Full Text Available In this article we study the semilinear singular elliptic problem $$\\displaylines{ -\\Delta u = \\frac{p(x}{u^{\\alpha}}\\quad \\text{in } \\Omega \\cr u = 0\\quad \\text{on } \\partial\\Omega,\\quad u>0 \\text{ in } \\Omega, }$$ where $\\Omega$ is a regular bounded domain of $\\mathbb R^{N}$, $\\alpha\\in\\mathbb R$, $p\\in C(\\Omega$ which behaves as $d(x^{-\\beta}$ as $x\\to\\partial\\Omega$ with $d$ the distance function up to the boundary and $0\\leq \\beta 1$.
Functional limb weakness and paralysis.
Stone, J; Aybek, S
2016-01-01
Functional (psychogenic) limb weakness describes genuinely experienced limb power or paralysis in the absence of neurologic disease. The hallmark of functional limb weakness is the presence of internal inconsistency revealing a pattern of symptoms governed by abnormally focused attention. In this chapter we review the history and epidemiology of this clinical presentation as well as its subjective experience highlighting the detailed descriptions of authors at the end of the 19th and early 20th century. We discuss the relevance that physiological triggers such as injury and migraine and psychophysiological events such as panic and dissociation have to understanding of mechanism and treatment. We review many different positive diagnostic features, their basis in neurophysiological testing and present data on sensitivity and specificity. Diagnostic bedside tests with the most evidence are Hoover's sign, the hip abductor sign, drift without pronation, dragging gait, give way weakness and co-contraction. © 2016 Elsevier B.V. All rights reserved.
Cosmology and the weak interaction
International Nuclear Information System (INIS)
Schramm, D.N.
1989-12-01
The weak interaction plays a critical role in modern Big Bang cosmology. This review will emphasize two of its most publicized cosmological connections: Big Bang nucleosynthesis and Dark Matter. The first of these is connected to the cosmological prediction of Neutrino Flavours, N ν ∼ 3 which is now being confirmed at SLC and LEP. The second is interrelated to the whole problem of galaxy and structure formation in the universe. This review will demonstrate the role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure. 87 refs., 3 figs., 5 tabs
Nonlinear waves and weak turbulence
Zakharov, V E
1997-01-01
This book is a collection of papers on dynamical and statistical theory of nonlinear wave propagation in dispersive conservative media. Emphasis is on waves on the surface of an ideal fluid and on Rossby waves in the atmosphere. Although the book deals mainly with weakly nonlinear waves, it is more than simply a description of standard perturbation techniques. The goal is to show that the theory of weakly interacting waves is naturally related to such areas of mathematics as Diophantine equations, differential geometry of waves, Poincaré normal forms, and the inverse scattering method.
Weak interactions at high energies
International Nuclear Information System (INIS)
Ellis, J.
1978-08-01
Review lectures are presented on the phenomenological implications of the modern spontaneously broken gauge theories of the weak and electromagnetic interactions, and some observations are made about which high energy experiments probe what aspects of gauge theories. Basic quantum chromodynamics phenomenology is covered including momentum dependent effective quark distributions, the transverse momentum cutoff, search for gluons as sources of hadron jets, the status and prospects for the spectroscopy of fundamental fermions and how fermions may be used to probe aspects of the weak and electromagnetic gauge theory, studies of intermediate vector bosons, and miscellaneous possibilities suggested by gauge theories from the Higgs bosons to speculations about proton decay. 187 references
Global existence result for the generalized Peterlin viscoelastic model
Czech Academy of Sciences Publication Activity Database
Lukáčová-Medviďová, M.; Mizerová, H.; Nečasová, Šárka; Renardy, M.
2017-01-01
Roč. 49, č. 4 (2017), s. 2950-2964 ISSN 0036-1410 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : Peterlin viscoelastic equations * global existence * weak solutions Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.648, year: 2016 http://epubs.siam.org/doi/abs/10.1137/16M1068505
Global existence result for the generalized Peterlin viscoelastic model
Czech Academy of Sciences Publication Activity Database
Lukáčová-Medviďová, M.; Mizerová, H.; Nečasová, Šárka; Renardy, M.
2017-01-01
Roč. 49, č. 4 (2017), s. 2950-2964 ISSN 0036-1410 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : Peterlin viscoelastic equations * global existence * weak solutions Subject RIV: BA - General Mathematics Impact factor: 1.648, year: 2016 http://epubs.siam.org/doi/abs/10.1137/16M1068505
Voltage Weak DC Distribution Grids
Hailu, T.G.; Mackay, L.J.; Ramirez Elizondo, L.M.; Ferreira, J.A.
2017-01-01
This paper describes the behavior of voltage weak DC distribution systems. These systems have relatively small system capacitance. The size of system capacitance, which stores energy, has a considerable effect on the value of fault currents, control complexity, and system reliability. A number of
Second threshold in weak interactions
Veltman, M.J.G.
1977-01-01
The point of view that weak interactions must have a second threshold below 300 – 600 GeV is developed. Above this threshold new physics must come in. This new physics may be the Higgs system, or some other nonperturbative system possibly having some similarities to the Higgs system. The limit of
Coverings, Networks and Weak Topologies
Czech Academy of Sciences Publication Activity Database
Dow, A.; Junnila, H.; Pelant, Jan
2006-01-01
Roč. 53, č. 2 (2006), s. 287-320 ISSN 0025-5793 R&D Projects: GA ČR GA201/97/0216 Institutional research plan: CEZ:AV0Z10190503 Keywords : Banach spaces * weak topologies * networks topologies Subject RIV: BA - General Mathematics
International Nuclear Information System (INIS)
Huterer, Dragan
2002-01-01
We study the power of upcoming weak lensing surveys to probe dark energy. Dark energy modifies the distance-redshift relation as well as the matter power spectrum, both of which affect the weak lensing convergence power spectrum. Some dark-energy models predict additional clustering on very large scales, but this probably cannot be detected by weak lensing alone due to cosmic variance. With reasonable prior information on other cosmological parameters, we find that a survey covering 1000 sq deg down to a limiting magnitude of R=27 can impose constraints comparable to those expected from upcoming type Ia supernova and number-count surveys. This result, however, is contingent on the control of both observational and theoretical systematics. Concentrating on the latter, we find that the nonlinear power spectrum of matter perturbations and the redshift distribution of source galaxies both need to be determined accurately in order for weak lensing to achieve its full potential. Finally, we discuss the sensitivity of the three-point statistics to dark energy
Submanifolds weakly associated with graphs
Indian Academy of Sciences (India)
theory by defining submanifolds weakly associated with graphs. We prove that, in a local sense, every submanifold satisfies such an association, and other general results. Finally, we study submanifolds associated with graphs either in low dimensions or belonging to some special families. Keywords. Almost Hermitian ...
Submanifolds weakly associated with graphs
Indian Academy of Sciences (India)
We establish an interesting link between differential geometry and graph theory by defining submanifolds weakly associated with graphs. We prove that, in a local sense, every submanifold satisfies such an association, and other general results. Finally, we study submanifolds associated with graphs either in low ...
Nonperturbative theory of weak pre- and post-selected measurements
Energy Technology Data Exchange (ETDEWEB)
Kofman, Abraham G., E-mail: kofmana@gmail.com; Ashhab, Sahel; Nori, Franco
2012-11-01
This paper starts with a brief review of the topic of strong and weak pre- and post-selected (PPS) quantum measurements, as well as weak values, and afterwards presents original work. In particular, we develop a nonperturbative theory of weak PPS measurements of an arbitrary system with an arbitrary meter, for arbitrary initial states of the system and the meter. New and simple analytical formulas are obtained for the average and the distribution of the meter pointer variable. These formulas hold to all orders in the weak value. In the case of a mixed preselected state, in addition to the standard weak value, an associated weak value is required to describe weak PPS measurements. In the linear regime, the theory provides the generalized Aharonov–Albert–Vaidman formula. Moreover, we reveal two new regimes of weak PPS measurements: the strongly-nonlinear regime and the inverted region (the regime with a very large weak value), where the system-dependent contribution to the pointer deflection decreases with increasing the measurement strength. The optimal conditions for weak PPS measurements are obtained in the strongly-nonlinear regime, where the magnitude of the average pointer deflection is equal or close to the maximum. This maximum is independent of the measurement strength, being typically of the order of the pointer uncertainty. In the optimal regime, the small parameter of the theory is comparable to the overlap of the pre- and post-selected states. We show that the amplification coefficient in the weak PPS measurements is generally a product of two qualitatively different factors. The effects of the free system and meter Hamiltonians are discussed. We also estimate the size of the ensemble required for a measurement and identify optimal and efficient meters for weak measurements. Exact solutions are obtained for a certain class of the measured observables. These solutions are used for numerical calculations, the results of which agree with the theory
The magnetosphere under weak solar wind forcing
Directory of Open Access Journals (Sweden)
C. J. Farrugia
2007-02-01
Full Text Available The Earth's magnetosphere was very strongly disturbed during the passage of the strong shock and the following interacting ejecta on 21–25 October 2001. These disturbances included two intense storms (Dst*≈−250 and −180 nT, respectively. The cessation of this activity at the start of 24 October ushered in a peculiar state of the magnetosphere which lasted for about 28 h and which we discuss in this paper. The interplanetary field was dominated by the sunward component [B=(4.29±0.77, −0.30±0.71, 0.49±0.45 nT]. We analyze global indicators of geomagnetic disturbances, polar cap precipitation, ground magnetometer records, and ionospheric convection as obtained from SuperDARN radars. The state of the magnetosphere is characterized by the following features: (i generally weak and patchy (in time low-latitude dayside reconnection or reconnection poleward of the cusps; (ii absence of substorms; (iii a monotonic recovery from the previous storm activity (Dst corrected for magnetopause currents decreasing from ~−65 to ~−35 nT, giving an unforced decreased of ~1.1 nT/h; (iv the probable absence of viscous-type interaction originating from the Kelvin-Helmholtz (KH instability; (v a cross-polar cap potential of just 20–30 kV; (vi a persistent, polar cap region containing (vii very weak, and sometimes absent, electron precipitation and no systematic inter-hemisphere asymmetry. Whereas we therefore infer the presence of a moderate amount of open flux, the convection is generally weak and patchy, which we ascribe to the lack of solar wind driver. This magnetospheric state approaches that predicted by Cowley and Lockwood (1992 but has never yet been observed.
Weakly Nonlinear Waves with Slowly-Varying Speed | Chikwendu ...
African Journals Online (AJOL)
A previously developed method of generating uniformly valid, multiple- scale asymptotic expansions for the solution of weakly nonlinear one-dimensional wave equations is applied to problems with slowly-varying speed. The method is also shown to be applicable specifically to periodic initial data.
An infinite-dimensional weak KAM theory via random variables
Gomes, Diogo A.
2016-08-31
We develop several aspects of the infinite-dimensional Weak KAM theory using a random variables\\' approach. We prove that the infinite-dimensional cell problem admits a viscosity solution that is a fixed point of the Lax-Oleinik semigroup. Furthermore, we show the existence of invariant minimizing measures and calibrated curves defined on R.
Linear operator inequalities for strongly stable weakly regular linear systems
Curtain, RF
2001-01-01
We consider the question of the existence of solutions to certain linear operator inequalities (Lur'e equations) for strongly stable, weakly regular linear systems with generating operators A, B, C, 0. These operator inequalities are related to the spectral factorization of an associated Popov
Weak polyelectrolyte complexation driven by associative charging
Rathee, Vikramjit S.; Zervoudakis, Aristotle J.; Sidky, Hythem; Sikora, Benjamin J.; Whitmer, Jonathan K.
2018-03-01
Weak polyelectrolytes are relevant for a wide range of fields; in particular, they have been investigated as "smart" materials for chemical separations and drug delivery. The charges on weak polyelectrolytes are dynamic, causing polymer chains to adopt different equilibrium conformations even with relatively small changes to the surrounding environment. Currently, there exists no comprehensive picture of this behavior, particularly where polymer-polymer interactions have the potential to affect charging properties significantly. In this study, we elucidate the novel interplay between weak polyelectrolyte charging and complexation behavior through coupled molecular dynamics and Monte Carlo simulations. Specifically, we investigate a model of two equal-length and oppositely charging polymer chains in an implicit salt solution represented through Debye-Hückel interactions. The charging tendency of each chain, along with the salt concentration, is varied to determine the existence and extent of cooperativity in charging and complexation. Strong cooperation in the charging of these chains is observed at large Debye lengths, corresponding to low salt concentrations, while at lower Debye lengths (higher salt concentrations), the chains behave in apparent isolation. When the electrostatic coupling is long-ranged, we find that a highly charged chain strongly promotes the charging of its partner chain, even if the environment is unfavorable for an isolated version of that partner chain. Evidence of this phenomenon is supported by a drop in the potential energy of the system, which does not occur at the lower Debye lengths where both potential energies and charge fractions converge for all partner chain charging tendencies. The discovery of this cooperation will be helpful in developing "smart" drug delivery mechanisms by allowing for better predictions for the dissociation point of delivery complexes.
Pierson, Nicholas A; Makarov, Alexey A; Strulson, Christopher A; Mao, Yun; Mao, Bing
2017-05-05
Development of methodologies for studying protein higher-order structure in solution helps to establish a better understanding of the intrinsic link between protein conformational structure and biological function and activity. The goal of this study was to demonstrate a simultaneous screening approach for global protein conformational changes in solution through the combination of ion mobility spectrometry-mass spectrometry (IMS-MS) with differential hydrogen-deuterium exchange (ΔHDX) on the size-exclusion chromatography (SEC) platform in a single on-line workflow. A semi-automated experimental setup based on the use of SEC on-column conditions allowed for tracking of protein conformational changes in solution as a function of acetonitrile concentration. In this setup, the SEC protein elution data was complemented by the ΔHDX profile which showed global protein conformational changes as a difference in the number of deuterons exchanged to protons. The ΔHDX data, in turn, was complemented by the changes in the drift time by IMS-MS. All three orthogonal techniques were applied for studying global higher-order structure of the proteins ubiquitin, cytochrome c and myoglobin, in solution simultaneously. The described approach allows for the use of a crude sample (or mixture of proteins) and could be suitable for rapid comparison of protein batch-to-batch higher-order structure or for optimizing conditions for enzymatic reactions. Copyright © 2017 Elsevier B.V. All rights reserved.
Weak neutral-current interactions
International Nuclear Information System (INIS)
Barnett, R.M.
1978-08-01
The roles of each type of experiment in establishing uniquely the values of the the neutral-current couplings of u and d quarks are analyzed together with their implications for gauge models of the weak and electromagnetic interactions. An analysis of the neutral-current couplings of electrons and of the data based on the assumption that only one Z 0 boson exists is given. Also a model-independent analysis of parity violation experiments is discussed. 85 references
History of the weak interactions
International Nuclear Information System (INIS)
Lee, T.D.
1987-01-01
At the 'Jackfest' marking the 65th birthday of Jack Steinberger (see July/August 1986 issue, page 29), T.D. Lee gave an account of the history of the weak interactions. This edited version omits some of Lee's tributes to Steinberger, but retains the impressive insight into the subtleties of a key area of modern physics by one who played a vital role in its development. (orig./HSI).
Weak neutral-current interactions
Energy Technology Data Exchange (ETDEWEB)
Barnett, R.M.
1978-08-01
The roles of each type of experiment in establishing uniquely the values of the the neutral-current couplings of u and d quarks are analyzed together with their implications for gauge models of the weak and electromagnetic interactions. An analysis of the neutral-current couplings of electrons and of the data based on the assumption that only one Z/sup 0/ boson exists is given. Also a model-independent analysis of parity violation experiments is discussed. 85 references. (JFP)
Ravi, O.
2015-01-01
called weakly Iπg-open sets in ideal topological spaces is introduced and the notion of weakly Iπg-closed sets in ideal topologicalspaces is studied. The relationships of weakly Iπg-closed sets andvarious properties of weakly Iπg-closed sets are investigated
International Nuclear Information System (INIS)
Gaillard, M.K.
1978-08-01
The properties that may help to identify the two additional quark flavors that are expected to be discovered. These properties are lifetime, branching ratios, selection rules, and lepton decay spectra. It is also noted that CP violation may manifest itself more strongly in heavy particle decays than elsewhere providing a new probe of its origin. The theoretical progress in the understanding of nonleptonic transitions among lighter quarks, nonleptonic K and hyperon decay amplitudes, omega minus and charmed particle decay predictions, and lastly the Kobayashi--Maskawa model for the weak coupling of heavy quarks together with the details of its implications for topology and bottomology are treated. 48 references
Strengths, weaknesses, opportunities and threats
DEFF Research Database (Denmark)
Bull, Joseph William; Jobstvogt, N.; Böhnke-Henrichs, A.
2016-01-01
. Such an assessment could form the basis for improving ES thinking, further embedding it into environmental decisions and management.The Young Ecosystem Services Specialists (YESS) completed a Strengths-Weaknesses-Opportunities-Threats (SWOT) analysis of ES through YESS member surveys. Strengths include the approach...... environmental awareness. Threats include resistance to change, and difficulty with interdisciplinary collaboration. Consideration of SWOT themes suggested five strategic areas for developing and implementing ES.The ES concept could improve decision-making related to natural resource use, and interpretation...
Nonlinear shock structure in a weakly ionised magnetoplasma
Directory of Open Access Journals (Sweden)
C. B. Dwivedi
1994-12-01
Full Text Available The formation of a neutral induced weak nonlinear shock structure in a weakly ionised magnetoplasma has been analytically investigated. Using the reductive perturbation method, basic dynamical equations of a three-component (electron, ion and neutral plasma have been reduced to a well-known Burger equation which can support a weak shock solution. Its stationary and initial value solutions have been derived to describe the characteristics of the weak shock profile. Asymptotic behaviour of the Burger solution results in a saw-tooth structure which has a practical implication to predict the nonlinear steepened structure of the nighttime irregularity in the lower portion of the Earth's ionosphere. Accordingly, it is suggested that the observation of saw-tooth shape of nighttime irregularity at 92 km could be attributed to the nonlinear saturation of the NILF mode instability as proposed by Dwivedi and Das in 1992. However, exact experimental verification of this suggestion requires more data on nighttime irregularity in the mesosphere and lower thermosphere (80-95 km for a wide range of scale sizes extending up to about 1 km and above.
Political corruption and weak state
Directory of Open Access Journals (Sweden)
Stojiljković Zoran
2013-01-01
Full Text Available The author starts from the hypothesis that it is essential for the countries of the region to critically assess the synergy established between systemic, political corruption and a selectively weak, “devious” nature of the state. Moreover, the key dilemma is whether the expanded practice of political rent seeking supports the conclusion that the root of all corruption is in the very existence of the state - particularly in excessive, selective and deforming state interventions and benefits that create a fertile ground for corruption? The author argues that the destructive combination of weak government and rampant political corruption is based on scattered state intervention, while also rule the parties cartel in the executive branch subordinate to parliament, the judiciary and the police. Corrupt exchange takes place with the absence of strong institutional framework and the precise rules of the political and electoral games, control of public finances and effective political and anti-monopoly legislation and practice included. Exit from the current situation can be seen in the realization of effective anticorruption strategy that integrates preventive and repressive measures and activities and lead to the establishment of principles of good governance. [Projekat Ministarstva nauke Republike Srbije, br. 179076: Politički identitet Srbije u regionalnom i globalnom kontekstu
Weak lensing and cosmological investigation
Acquaviva, V
2005-01-01
In the last few years the scientific community has been dealing with the challenging issue of identifying the dark energy component. We regard weak gravitational lensing as a brand new, and extremely important, tool for cosmological investigation in this field. In fact, the features imprinted on the cosmic microwave background radiation by the lensing from the intervening distribution of matter represent a pretty unbiased estimator, and can thus be used for putting constraints on different dark energy models. This is true in particular for the magnetic-type B-modes of CMB polarization, whose unlensed spectrum at large multipoles (l approximately=1000) is very small even in presence of an amount of gravitational waves as large as currently allowed by the experiments: therefore, on these scales the lensing phenomenon is the only responsible for the observed power, and this signal turns out to be a faithful tracer of the dark energy dynamics. We first recall the formal apparatus of the weak lensing in extended t...
Existence of solutions for a nonlinear hyperbolic-parabolic equation in a non-cylinder domain
Directory of Open Access Journals (Sweden)
Marcondes Rodrigues Clark
1996-01-01
Full Text Available In this paper, we study the existence of global weak solutions for the equationk2(xu″+k1(xu′+A(tu+|u|ρu=f (Iin the non-cylinder domain Q in Rn+1; k1 and k2 are bounded real functions, A(t is the symmetric operatorA(t=−∑i,j=1n∂∂xj(aij(x,t∂∂xi where aij and f are real functions given in Q. For the proof of existence of global weak solutions we use the Faedo-Galerkin method, compactness arguments and penalization.
Weak transitions in lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Maturana, G.
1984-01-01
Some techniques to calculate the effects of the strong interactions on the matrix elements of weak processes are described. The lattice formulation of Quantum Chromodynamics is used to account for the low energy gluons, and the corresponding numerical methods are explained. The high energy contributions are included in effective lagrangians and the problem of matching the different scales related to the renormalization of the operators and wavefunctions is also discussed. The ..delta..l = 1/2 enhancement rule and the K/sup 0/-anti-K/sup 0/ are used to illustrate these techniques and the results of a numerical calculation is reported. The values obtained are very encouraging and they certainly show good qualitative agreement with the experimental values. The emphasis is on general techniques, and in particular, several improvements to this particular calculation are proposed.
Nuclear beta decay and the weak interaction
International Nuclear Information System (INIS)
Kean, D.C.
1975-11-01
Short notes are presented on various aspects of nuclear beta decay and weak interactions including: super-allowed transitions, parity violation, interaction strengths, coupling constants, and the current-current formalism of weak interaction. (R.L.)
Weakly distributive modules. Applications to supplement submodules
Indian Academy of Sciences (India)
Abstract. In this paper, we define and study weakly distributive modules as a proper generalization of distributive modules. We prove that, weakly distributive supplemented modules are amply supplemented. In a weakly distributive supplemented module every submodule has a unique coclosure. This generalizes a result of ...
Fault zone fabric and fault weakness
Collettini, C.; Niemeijer, A.; Viti, C.; Marone, C.
2009-01-01
Geological and geophysical evidence suggests that some crustal faults are weak1–6 compared to laboratory measurements of frictional strength7. Explanations for fault weakness include the presence of weak minerals4, high fluid pressures within the fault core8,9 and dynamic processes such as
Practical approach to the patient with acute neuromuscular weakness.
Nayak, Rajeev
2017-07-16
Acute neuromuscular paralysis (ANMP) is a clinical syndrome characterized by rapid onset muscle weakness progressing to maximum severity within several days to weeks (less than 4 wk). Bulbar and respiratory muscle weakness may or may not be present. It is a common neurological emergency which requires immediate and careful investigations to determine the etiology because accurate diagnosis has significant impact on therapy and prognosis. Respiratory failure caused by neuromuscular weakness is considered as more critical than lung disease because its development may be insidious or subtle until sudden decompensation leads to life threatening hypoxia. Also, the arterial blood gas finding of severe hypoxemia, hypercapnia, and acidosis may not be apparent until respiratory failure is profound. Hence, the requirement for respiratory assistance should also be intensively and promptly investigated in all patients with neuromuscular disease. The disorder is classified based on the site of defect in motor unit pathway, i.e ., anterior horn cells, nerve root, peripheral nerve, neuromuscular junction or muscle. Identification of the cause is primarily based on a good medical history and detailed clinical examination supplemented with neurophysiologic investigations and sometimes few specific laboratory tests. Medical history and neurological examination should be focused on the onset, progression, pattern and severity of muscle weakness as well as cranial nerves testing and tests for autonomic dysfunction. Associated non neurological features like fever, rash or other skin lesions etc. should also be noted. Globally, Guillain-Barré syndrome is the most frequent cause of ANMP and accounts for the majority of cases of respiratory muscles weakness associated with neuromuscular disorders. Newly acquired neuromuscular weakness in intensive care unit patients consist of critical illness polyneuropathy, critical illness myopathy and drug induced neuromuscular weakness which may
Fairtrade, Food Security and Globalization: Building Alternative Food Systems
Directory of Open Access Journals (Sweden)
Martin Calisto Friant
2016-05-01
Full Text Available This article examines the politics and practices of Fairtrade certification in order to assess whether this alternative trading system could contribute to innovative solutions for global food security. The analysis begins by assessing the main challenges and problems characterizing the contemporary global food system. It then explores the history, vision and certification standards of the Fairtrade label. In the third section, the results of the impact studies of Fairtrade certification on producer livelihoods are discussed, analyzing the various strengths and weaknesses. Finally the article analyzes whether, and how, the Fairtrade system could positively contribute to improving global food security. To conclude this paper argues that the greatest strength of Fairtrate is not the certification mechanism itself but rather the social and environmental principles it represents. Fairtrade standards could serve to inform broader international policies, which could lead to a sustainable transformation of the global food system.
Ion cyclotron wave heating from the weak field -exterior- side in tokamaks
International Nuclear Information System (INIS)
Cotsaftis, M.
1983-10-01
Due to the possibility of representing the solution of the EM wave equations everywhere in a plasma medium by a simple and uniform asymptotic expansion, the problem of the weak field side RF heating has been globally and self-consistently approached. Both propagation and absorption have been together included all along from the source - the antennas - to the sink - the plasma paticles. It is shown that the heating efficiency has a maximum in terms of the two main parameters, antenna width and minority concentration. This means that large width antennas presently considered are not the best ones for heating. Further more, the part of the RF power which is not used to heat the plasma particle is shown to heat particles in the peripheral plasma in the shadow of the limiter by collisional heating. These heated particles in turn are producing extra impurity influx by increased sputtering. This is why operating the weak field size RF heating at optimum values in order to minimize the impurity production is so important in view of future large size experiments. It is shown that, though impurity production can be significantly reduced at optimum, it is not possible to reduce it further by using radial resonant type structure of the EM wave, because of the mismatch created by the large toroidal spead of the fast magnetosonic waves. As a result it is not sure today this way of heating will be efficient enough to stay safety within the thermonuclear purity requirements for a conventionnal tokamak
Strong Plate, Weak Slab Dichotomy
Petersen, R. I.; Stegman, D. R.; Tackley, P.
2015-12-01
Models of mantle convection on Earth produce styles of convection that are not observed on Earth.Moreover non-Earth-like modes, such as two-sided downwellings, are the de facto mode of convection in such models.To recreate Earth style subduction, i.e. one-sided asymmetric recycling of the lithosphere, proper treatment of the plates and plate interface are required. Previous work has identified several model features that promote subduction. A free surface or pseudo-free surface and a layer of material with a relatively low strength material (weak crust) allow downgoing plates to bend and slide past overriding without creating undue stress at the plate interface. (Crameri, et al. 2012, GRL)A low viscosity mantle wedge, possibly a result of slab dehydration, decouples the plates in the system. (Gerya et al. 2007, Geo)Plates must be composed of material which, in the case of the overriding plate, are is strong enough to resist bending stresses imposed by the subducting plate and yet, as in the case of the subducting plate, be weak enough to bend and subduct when pulled by the already subducted slab. (Petersen et al. 2015, PEPI) Though strong surface plates are required for subduction such plates may present a problem when they encounter the lower mantle.As the subducting slab approaches the higher viscosity, lower mantle stresses are imposed on the tip.Strong slabs transmit this stress to the surface.There the stress field at the plate interface is modified and potentially modifies the style of convection. In addition to modifying the stress at the plate interface, the strength of the slab affects the morphology of the slab at the base of the upper mantle. (Stegman, et al 2010, Tectonophysics)Slabs that maintain a sufficient portion of their strength after being bent require high stresses to unbend or otherwise change their shape.On the other hand slabs that are weakened though the bending process are more amenable to changes in morphology. We present the results of
A Universe without Weak Interactions
Energy Technology Data Exchange (ETDEWEB)
Harnik, Roni; Kribs, Graham D.; Perez, Gilad
2006-04-07
A universe without weak interactions is constructed that undergoes big-bang nucleosynthesis, matter domination, structure formation, and star formation. The stars in this universe are able to burn for billions of years, synthesize elements up to iron, and undergo supernova explosions, dispersing heavy elements into the interstellar medium. These definitive claims are supported by a detailed analysis where this hypothetical ''Weakless Universe'' is matched to our Universe by simultaneously adjusting Standard Model and cosmological parameters. For instance, chemistry and nuclear physics are essentially unchanged. The apparent habitability of the Weakless Universe suggests that the anthropic principle does not determine the scale of electroweak breaking, or even require that it be smaller than the Planck scale, so long as technically natural parameters may be suitably adjusted. Whether the multi-parameter adjustment is realized or probable is dependent on the ultraviolet completion, such as the string landscape. Considering a similar analysis for the cosmological constant, however, we argue that no adjustments of other parameters are able to allow the cosmological constant to raise up even remotely close to the Planck scale while obtaining macroscopic structure. The fine-tuning problems associated with the electroweak breaking scale and the cosmological constant therefore appear to be qualitatively different from the perspective of obtaining a habitable universe.
Measurements of weak conversion lines
International Nuclear Information System (INIS)
Feoktistov, A.I.; Frantsev, Yu.E.
1979-01-01
Described is a new methods for measuring weak conversion lines with the help of the β spectrometer of the π √ 2 type which permits to increase the reliability of the results obtained. According to this method the measurements were carried out by short series with the storage of the information obtained on the punched tape. The spectrometer magnetic field was stabilized during the measuring of the conversion spectra with the help of three nmr recorders. Instead of the dependence of the pulse calculation rate on the magnetic field value was measured the dependence of the calculation rate on the value of the voltage applied between the source and the spectrometer chamber. A short description of the automatic set-up for measuring conversion lines according to the method proposed is given. The main set-up elements are the voltage multiplexer timer, printer, scaler and the pulse analyzer. With the help of the above methods obtained is the K 1035, 8 keV 182 Ta line. It is obtained as a result of the composition of 96 measurement series. Each measurement time constitutes 640 s 12 points are taken on the line
Methodology for analyzing weak spectra
International Nuclear Information System (INIS)
Yankovich, T.L.; Swainson, I.P.
2000-02-01
There is considerable interest in quantifying radionuclide transfer between environmental compartments. However, in many cases, it can be a challenge to detect concentrations of gamma-emitting radionuclides due to their low levels in environmental samples. As a result, it is valuable to develop analytical protocols to ensure consistent analysis of the areas under weak peaks. The current study has focused on testing how reproducibly peak areas and baselines can be determined using two analytical approaches. The first approach, which can be carried out using Maestro software, involves extracting net counts under a curve without fitting a functional form to the peak, whereas the second approach, which is used by most other peak fitting programs, determines net counts from spectra by fitting a Gaussian form to the data. It was found that the second approach produces more consistent peak area and baseline measurements, with the ability to de-convolute multiple, overlapping peaks. In addition, programs, such as Peak Fit, which can be used to fit a form to spectral data, often provide goodness of fit analyses, since the Gaussian form can be described using a characteristic equation against which peak data can be tested for their statistical significance. (author)
The Geometry And Significance Of Weak Energy
Parks, A D
2000-01-01
Summary: The theory of weak values for quantum mechanical observables has come to serve as a useful basis for contemporary discussions concerning such varied topics as the tunnelling-time controversy and quantum stochastic processes. An intrinsic complex-valued weak energy has recently been observed experimentally and reported in the literature. In this paper it is shown that: (a) the real and imaginary valued parts of this weak energy have geometric interpretations related to a phase acquired from parallel transport in Hilbert space and the variational dynamics occurring in the associated projective Hilbert space, respectively; (b) the weak energy defines functions which translate correlation amplitudes and probabilities in time; (c) correlation probabilities can be controlled by manipulating the weak energy and there exists a condition of weak stationarity that guarantees their time invariance; and (d) a time-weak energy uncertainty relation of the usual form prevails when a suitable set of dynamical constr...
Czech Academy of Sciences Publication Activity Database
Hakl, Robert; Aguerrea, M.
2017-01-01
Roč. 147, č. 6 (2017), s. 1119-1168 ISSN 0308-2105 Institutional support: RVO:67985840 Keywords : functional differential equations * boundary-value problems * global existence Subject RIV: BA - General Mathematics OBOR OECD: Applied mathematics Impact factor: 1.158, year: 2016
Wada, Y.; Flörke, M.; Hanasaki, N.; Eisner, S.; Fischer, G.; Tramberend, S.; Satoh, Y.; Van Vliet, M. T H; Yillia, P.; Ringler, C.; Burek, P.; Wiberg, D.
2016-01-01
To sustain growing food demand and increasing standard of living, global water use increased by nearly 6 times during the last 100 years, and continues to grow. As water demands get closer and closer to the water availability in many regions, each drop of water becomes increasingly valuable and
Czech Academy of Sciences Publication Activity Database
Hakl, Robert; Aguerrea, M.
2017-01-01
Roč. 147, č. 6 (2017), s. 1119-1168 ISSN 0308-2105 Institutional support: RVO:67985840 Keywords : functional differential equations * boundary-value problems * global existence Subject RIV: BA - General Mathematics Impact factor: 1.158, year: 2016
Spatial evolutionary games with weak selection.
Nanda, Mridu; Durrett, Richard
2017-06-06
Recently, a rigorous mathematical theory has been developed for spatial games with weak selection, i.e., when the payoff differences between strategies are small. The key to the analysis is that when space and time are suitably rescaled, the spatial model converges to the solution of a partial differential equation (PDE). This approach can be used to analyze all [Formula: see text] games, but there are a number of [Formula: see text] games for which the behavior of the limiting PDE is not known. In this paper, we give rules for determining the behavior of a large class of [Formula: see text] games and check their validity using simulation. In words, the effect of space is equivalent to making changes in the payoff matrix, and once this is done, the behavior of the spatial game can be predicted from the behavior of the replicator equation for the modified game. We say predicted here because in some cases the behavior of the spatial game is different from that of the replicator equation for the modified game. For example, if a rock-paper-scissors game has a replicator equation that spirals out to the boundary, space stabilizes the system and produces an equilibrium.
Mappings on weakly Lindelöf and weakly regular-Lindel¨of spaces
Directory of Open Access Journals (Sweden)
Anwar Jabor Fawakhreh
2011-10-01
Full Text Available In this paper we study the effect of mappings and some decompositions of continuity on weakly Lindelöf spaces and weakly regular-Lindelöf spaces. We show that some mappings preserve these topological properties. We also show that the image of a weakly Lindelöf space (resp. weakly regular-Lindelöf space under an almost continuous mapping is weakly Lindelöf (resp. weakly regular-Lindelöf. Moreover, the image of a weakly regular-Lindelöf space under a precontinuous and contracontinuousmapping is Lindelöf.
Weak boson emission in hadron collider processes
International Nuclear Information System (INIS)
Baur, U.
2007-01-01
The O(α) virtual weak radiative corrections to many hadron collider processes are known to become large and negative at high energies, due to the appearance of Sudakov-like logarithms. At the same order in perturbation theory, weak boson emission diagrams contribute. Since the W and Z bosons are massive, the O(α) virtual weak radiative corrections and the contributions from weak boson emission are separately finite. Thus, unlike in QED or QCD calculations, there is no technical reason for including gauge boson emission diagrams in calculations of electroweak radiative corrections. In most calculations of the O(α) electroweak radiative corrections, weak boson emission diagrams are therefore not taken into account. Another reason for not including these diagrams is that they lead to final states which differ from that of the original process. However, in experiment, one usually considers partially inclusive final states. Weak boson emission diagrams thus should be included in calculations of electroweak radiative corrections. In this paper, I examine the role of weak boson emission in those processes at the Fermilab Tevatron and the CERN LHC for which the one-loop electroweak radiative corrections are known to become large at high energies (inclusive jet, isolated photon, Z+1 jet, Drell-Yan, di-boson, tt, and single top production). In general, I find that the cross section for weak boson emission is substantial at high energies and that weak boson emission and the O(α) virtual weak radiative corrections partially cancel
The motion of the rigid body in viscous fluid including collisions. Global solvability result
Czech Academy of Sciences Publication Activity Database
Chemetov, N.; Nečasová, Šárka
2017-01-01
Roč. 34, April (2017), s. 416-445 ISSN 1468-1218 R&D Projects: GA ČR GA16-03230S Institutional support: RVO:67985840 Keywords : rigid body * global weak solution * collisions in finite time Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.659, year: 2016 http://www. sciencedirect .com/science/article/pii/S1468121816301146
The motion of the rigid body in viscous fluid including collisions. Global solvability result
Czech Academy of Sciences Publication Activity Database
Chemetov, N.; Nečasová, Šárka
2017-01-01
Roč. 34, April (2017), s. 416-445 ISSN 1468-1218 R&D Projects: GA ČR GA16-03230S Institutional support: RVO:67985840 Keywords : rigid body * global weak solution * collisions in finite time Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.659, year: 2016 http://www.sciencedirect.com/science/article/pii/S1468121816301146
Czech Academy of Sciences Publication Activity Database
Nečasová, Šárka; Wolf, J.
2016-01-01
Roč. 36, č. 3 (2016), s. 1539-1562 ISSN 1078-0947 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : incompressible fluid * motion of rigid body * strong solutions Subject RIV: BA - General Mathematics Impact factor: 1.099, year: 2016 http://www.aimsciences.org/journals/displayArticlesnew.jsp?paperID=11589
Directory of Open Access Journals (Sweden)
M. L. Santos
2007-04-01
in a non cylindrical domain of $\\mathbb{R}^{n+1}$ $(n\\ge1$ under suitable hypothesis on the scalar functions $M$, $h$, $g_1$ and $g_2$, and where $\\alpha$ is a positive constant. We show that such dissipation is strong enough to produce uniform rate of decay. Besides, the coupling is nonlinear which brings up some additional difficulties, which plays the problem interesting. We establish existence and uniqueness of regular solutions for any $n\\ge 1$.
Classical field approach to quantum weak measurements.
Dressel, Justin; Bliokh, Konstantin Y; Nori, Franco
2014-03-21
By generalizing the quantum weak measurement protocol to the case of quantum fields, we show that weak measurements probe an effective classical background field that describes the average field configuration in the spacetime region between pre- and postselection boundary conditions. The classical field is itself a weak value of the corresponding quantum field operator and satisfies equations of motion that extremize an effective action. Weak measurements perturb this effective action, producing measurable changes to the classical field dynamics. As such, weakly measured effects always correspond to an effective classical field. This general result explains why these effects appear to be robust for pre- and postselected ensembles, and why they can also be measured using classical field techniques that are not weak for individual excitations of the field.
Weakly distributive modules. Applications to supplement submodules
Indian Academy of Sciences (India)
It is well-known that, if f : M → N is an isomorphism, then there is a one-to-one corres- pondence between the submodules of M and the submodules of N. Therefore, any module. (lattice) isomorphic to a weakly distributive module, is itself weakly distributive. Lemma 2.1. Let M be a weakly distributive module and f : M → N be ...
Robust weak measurements on finite samples
International Nuclear Information System (INIS)
Tollaksen, Jeff
2007-01-01
A new weak measurement procedure is introduced for finite samples which yields accurate weak values that are outside the range of eigenvalues and which do not require an exponentially rare ensemble. This procedure provides a unique advantage in the amplification of small nonrandom signals by minimizing uncertainties in determining the weak value and by minimizing sample size. This procedure can also extend the strength of the coupling between the system and measuring device to a new regime
Are weak and electromagnetic interactions unified
International Nuclear Information System (INIS)
Dombey, N.
1983-01-01
This chapter examines how well the standard electroweak model agrees with experiment. Attempts to explain to a nonparticle physicist why weak and electromagnetic interactions are unified. Discusses the Glashow model (unified SU(2)xU(1)); some basic questions; an alternative viewpoint; unified theories; non-unified theories; and weak interactions as strong interactions. Concludes that SU(2)xU(1) is a good phenomenological model for weak and electromagnetic interactions in the energy region accessible to experiment
Joint Global Change Research Institute (JGCRI)
Federal Laboratory Consortium — The Joint Global Change Research Institute (JGCRI) is dedicated to understanding the problems of global climate change and their potential solutions. The Institute...
International Nuclear Information System (INIS)
Pando L, C.L.; Doedel, E.J.
2004-07-01
We investigate the onset of chaotic dynamics of the one-dimensional discrete nonlinear Schroedinger equation (DNLSE) with periodic boundary conditions in the presence of a single on-site defect. This model describes a ring of weakly- coupled Bose-Einstein condensates. We focus on the transition to global stochasticity in three different scenarios as the defect is changed. We make use of a suitable Poincare section and continuation methods. Numerical continuation enables us to find different families of stationary solutions, where certain bifurcations lead to global stochasticity. The global stochasticity is characterized by chaotic symbolic synchronization between the population inversions of certain pairs of condensates. We have seen that the Poincare cycles are useful to gain insight in the dynamics of this problem. Indeed, the return maps of the Poincare cycles have been used successfully to follow the motion along the stochastic layers of different resonances in the chaotic self-trapping regime. Moreover, the time series of the Poincare cycles suggests that in the global stochasticity regime the dynamics is, to some extent, Markovian, in spite of the fact that the condensates are phase locked with almost the same phase. This phase locking induces a peculiar local interference of the matter waves of the condensates. (author)
Correspondence propagation with weak priors.
Wang, Huan; Yan, Shuicheng; Liu, Jianzhuang; Tang, Xiaoou; Huang, Thomas S
2009-01-01
For the problem of image registration, the top few reliable correspondences are often relatively easy to obtain, while the overall matching accuracy may fall drastically as the desired correspondence number increases. In this paper, we present an efficient feature matching algorithm to employ sparse reliable correspondence priors for piloting the feature matching process. First, the feature geometric relationship within individual image is encoded as a spatial graph, and the pairwise feature similarity is expressed as a bipartite similarity graph between two feature sets; then the geometric neighborhood of the pairwise assignment is represented by a categorical product graph, along which the reliable correspondences are propagated; and finally a closed-form solution for feature matching is deduced by ensuring the feature geometric coherency as well as pairwise feature agreements. Furthermore, our algorithm is naturally applicable for incorporating manual correspondence priors for semi-supervised feature matching. Extensive experiments on both toy examples and real-world applications demonstrate the superiority of our algorithm over the state-of-the-art feature matching techniques.
A note on Weak Stability Boundaries
García González, Fernando; Gómez Muntané, Gerard
2006-01-01
This paper is devoted to clarify the algorithmic definition of the weak stability boundary in the framework of the planar Restricted Three Body Problem. The role of the invariant hyperbolic manifolds associated to the central manifolds of the libration points L1 and L2, as boundary of the weak stability region, is shown Peer Reviewed
Staggering towards a calculation of weak amplitudes
Energy Technology Data Exchange (ETDEWEB)
Sharpe, S.R.
1988-09-01
An explanation is given of the methods required to calculate hadronic matrix elements of the weak Hamiltonians using lattice QCD with staggered fermions. New results are presented for the 1-loop perturbative mixing of the weak interaction operators. New numerical techniques designed for staggered fermions are described. A preliminary result for the kaon B parameter is presented. 24 refs., 3 figs.
Staggering towards a calculation of weak amplitudes
International Nuclear Information System (INIS)
Sharpe, S.R.
1988-09-01
An explanation is given of the methods required to calculate hadronic matrix elements of the weak Hamiltonians using lattice QCD with staggered fermions. New results are presented for the 1-loop perturbative mixing of the weak interaction operators. New numerical techniques designed for staggered fermions are described. A preliminary result for the kaon B parameter is presented. 24 refs., 3 figs
Weak interaction: past answers, present questions
International Nuclear Information System (INIS)
Ne'eman, Y.
1977-02-01
A historical sketch of the weak interaction is presented. From beta ray to pion decay, the V-A theory of Marshak and Sudarshan, CVC principle of equivalence, universality as an algebraic condition, PCAC, renormalized weak Hamiltonian in the rehabilitation of field theory, and some current issues are considered in this review. 47 references
Common fixed points for weakly compatible maps
Indian Academy of Sciences (India)
Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45
flood of papers involving contractive definition that do not require the continuity of T . This result was further generalized and extended in various ways by many authors. On the other hand Sessa [11] defined weak commutativity and proved common fixed point theorem for weakly commuting maps. Further Jungck [5] ...
Optimization of strong and weak coordinates
Swart, M.; Bickelhaupt, F.M.
2006-01-01
We present a new scheme for the geometry optimization of equilibrium and transition state structures that can be used for both strong and weak coordinates. We use a screening function that depends on atom-pair distances to differentiate strong coordinates from weak coordinates. This differentiation
Moving Beyond Weak Identifiers for Proxemic Interaction
DEFF Research Database (Denmark)
Sørensen, Henrik; Kjeldskov, Jesper
2013-01-01
is significantly closer than what is actually the case. This makes the smartphone a weak identifier for applications that need to track persons. With a focus on feasible interaction design, we present a concept and prototype of a platform, which seek to support proxemic interaction beyond weak identifiers...
Towards a classification of weak hand holds
Kimmelman, V.; Sáfár, A.; Crasborn, O.
2016-01-01
The two symmetrical manual articulators (the hands) in signed languages are a striking modalityspecific phonetic property. The weak hand can maintain the end position of an articulation while the other articulator continues to produce additional signs. This weak hand spreading (hold) has been
Weak measurements with a qubit meter
DEFF Research Database (Denmark)
Wu, Shengjun; Mølmer, Klaus
2009-01-01
We derive schemes to measure the so-called weak values of quantum system observables by coupling of the system to a qubit meter system. We highlight, in particular, the meaning of the imaginary part of the weak values, and show how it can be measured directly on equal footing with the real part...
Black, Carrie; Germaschewski, Kai; Bhattacharjee, Amitava; Ng, C. S.
2013-01-01
It has been demonstrated that in the presence of weak collisions, described by the Lenard-Bernstein collision operator, the Landau-damped solutions become true eigenmodes of the system and constitute a complete set. We present numerical results from an Eulerian Vlasov code that incorporates the Lenard-Bernstein collision operator. The effect of the collisions on the numerical recursion phenomenon seen in Vlasov codes is discussed. The code is benchmarked against exact linear eigenmode solutions in the presence of weak collisions, and a spectrum of Landau-damped solutions is determined within the limits of numerical resolution. Tests of the orthogonality and the completeness relation are presented.
Kimizuka, M; Munakata, T; Rosinberg, M L
2010-10-01
We consider a network of N noisy bistable elements with global time-delayed couplings. In a two-state description, where elements are represented by Ising spins, the collective dynamics is described by an infinite hierarchy of coupled master equations which was solved at the mean-field level in the thermodynamic limit. When the number of elements is finite, as is the case in actual laser networks, an analytical description was deemed so far intractable and numerical studies seemed to be necessary. In this paper we consider the case of two interacting elements and show that a partial analytical description of the stationary state is possible if the stochastic process is time symmetric. This requires some relationship between the transition rates to be satisfied.
Persisting weakness after withdrawal of a statin.
Mygland, Åse; Ljøstad, Unn; Krossnes, Bård Kronen
2014-04-08
An 81-year-old woman treated with simvastatin for several years followed by atorvastatin for about 1 year presented with fatigue, weakness and unsteady gait. The finding of elevated creatine kinase (CK) and symmetric muscle weakness around shoulders and hips led to suspicion of a toxic statin-associated myopathy. Atorvastatin was withdrawn, but her weakness persisted. Owing to persisting weakness, an autoimmune myopathy (myositis) was suspected, but initially disregarded since a muscle biopsy showed necrotic muscle fibres without inflammatory cell infiltrates and myositis-specific autoantibodies were absent. After 18 months with slowly progressive weakness and increasing CK values, awareness of new knowledge about autoimmunity as a cause of necrotic myopathy, led to a successful treatment trial with intravenous immunoglobulines, followed by steroids and metothrexate. Antibodies to the target enzyme of statins (HMGCR (3-hydroksy-3-methylglutaryl-coenzyme A reductase)) were detected in her serum, and she was diagnosed with autoimmune necrotic myositis probably triggered by atorvastatin.
International Nuclear Information System (INIS)
Makhalov, A S; Nikolaenko, V P
2003-01-01
This paper is a survey of results concerning the three-dimensional Navier-Stokes and Euler equations with initial data characterized by uniformly large vorticity. The existence of regular solutions of the three-dimensional Navier-Stokes equations on an unbounded time interval is proved for large initial data both in R 3 and in bounded cylindrical domains. Moreover, the existence of smooth solutions on large finite time intervals is established for the three-dimensional Euler equations. These results are obtained without additional assumptions on the behaviour of solutions for t>0. Any smooth solution is not close to any two-dimensional manifold. Our approach is based on the computation of singular limits of rapidly oscillating operators, non-linear averaging, and a consideration of the mutual absorption of non-linear oscillations of the vorticity field. The use of resonance conditions, methods from the theory of small divisors, and non-linear averaging of almost periodic functions leads to the limit resonant Navier-Stokes equations. Global solubility of these equations is proved without any conditions on the three-dimensional initial data. The global regularity of weak solutions of three-dimensional Navier-Stokes equations with uniformly large vorticity at t=0 is proved by using the regularity of weak solutions and the strong convergence
On weakly hyperbolic spaces and a convergence-extension theorem in weakly hyperbolic spaces
International Nuclear Information System (INIS)
Duc, Pham Viet
2002-11-01
In this article we prove some properties of the weakly hyperbolic spaces. Moreover, a convergence-extension theorem for analytic hypersurfaces (not necessarily with normal crossings) in weakly hyperbolic spaces is given. (author)
Characterization of zonal flow generation in weak electrostatic turbulence
Energy Technology Data Exchange (ETDEWEB)
Negrea, M; Petrisor, I [Department of Physics, Association Euratom-MEdC, Romania, University of Craiova, 13 A.I. Cuza Street, 200585 Craiova (Romania); Weyssow, B [Physique Statistique-Plasmas, Association Euratom-Etat Belge, Universite Libre de Bruxelles, Campus Plaine, Bd. du Triomphe, 1050 Bruxelles (Belgium)], E-mail: mnegrea@yahoo.com
2008-05-15
The influence of the diamagnetic Kubo number, which is proportional to the diamagnetic drift velocity, on the zonal flow generation by an anisotropic stochastic electrostatic potential is considered from a semi-analytic point of view. The analysis is performed in the weak turbulence limit and as an analytical tool the decorrelation trajectory method is used. It is shown that the fragmentation of the drift wave structures (a signature of the zonal flow generation) is influenced not only by the anisotropy parameter and the electrostatic Kubo number as expected, but also by the diamagnetic Kubo number. Global Lagrangian averages of characteristic quantities are calculated and interpreted.
Solution of Finite Element Equations
DEFF Research Database (Denmark)
Krenk, Steen
An important step in solving any problem by the finite element method is the solution of the global equations. Numerical solution of linear equations is a subject covered in most courses in numerical analysis. However, the equations encountered in most finite element applications have some special...... features that justify the development of specialized solution algorithms....
Weak and electromagnetic interactions in nuclei
International Nuclear Information System (INIS)
Klapdor, H.V.
1986-01-01
The International Symposium W.E.I.N. 1986 brought together leading experts in the fields of nuclear and elementary particle physics, astrophysics and cosmology. In addition to current problems in nuclear physics (weak and electromagnetic nuclear properties, electroweak interactions in nuclei, exotic nuclei) this book presents fascinating contributions that arise from the interaction among these fields: lepton number violation and neutrino mass; muon physics; weak interactions and fundamental symmetries; fundamental decays; basic experiments for GUTs; weak interactions and astrophysics; GUTs, SUSYs and the early Universe. The book demonstrates that in this context nuclear physics promises exciting future developments. (orig.)
International Nuclear Information System (INIS)
Wu Shiliang; Li Wantong
2009-01-01
This paper deals with the global asymptotic stability and uniqueness (up to translation) of bistable traveling fronts in a class of reaction-diffusion systems. The known results do not apply in solving these problems because the reaction terms do not satisfy the required monotone condition. To overcome the difficulty, a weak monotone condition is proposed for the reaction terms, which is called interval monotone condition. Under such a weak monotone condition, the existence and comparison theorem of solutions is first established for reaction-diffusion systems on R by appealing to the theory of abstract differential equations. The global asymptotic stability and uniqueness (up to translation) of bistable traveling fronts are then proved by the elementary super- and sub-solution comparison and squeezing methods for nonlinear evolution equations. Finally, these abstract results are applied to a two species competition-diffusion model and a system modeling man-environment-man epidemics.
Gaussian beam diffraction in weakly anisotropic inhomogeneous media
Energy Technology Data Exchange (ETDEWEB)
Kravtsov, Yu.A., E-mail: kravtsov@am.szczecin.p [Institute of Physics, Maritime University of Szczecin, Szczecin 70-500 (Poland); Space Research Institute, Russian Academy of Science, Moscow 117 997 (Russian Federation); Berczynski, P., E-mail: pawel.berczynski@ps.p [Institute of Physics, West Pomeranian University of Technology, Szczecin 70-310 (Poland); Bieg, B., E-mail: b.bieg@am.szczecin.p [Institute of Physics, Maritime University of Szczecin, Szczecin 70-500 (Poland)
2009-08-10
Combination of quasi-isotropic approximation (QIA) of geometric optics with paraxial complex geometric optics (PCGO) is suggested, which allows describing both diffraction and polarization evolution of Gaussian electromagnetic beams in weakly anisotropic inhomogeneous media. Combination QIA/PCGO reduces Maxwell equations to the system of the ordinary differential equations of the first order and radically simplifies solution of various problems, related to microwave plasma diagnostics, including plasma polarimetry, interferometry and refractometry in thermonuclear reactors. Efficiency of the method is demonstrated by the example of electromagnetic beam diffraction in a linear layer of magnetized plasma with parameters, modeling tokamak plasma in the project ITER.
Asymptotic behavior of a weakly forced dry friction oscillator
Directory of Open Access Journals (Sweden)
J. Ildefonso Diaz
2007-05-01
Full Text Available This note is devoted to stick-slip aspects of the motion of a dry friction damped oscillator under weak irregular forcing. Our main result complements [10, Theorem 3.(a] and is also related to [1], where a non-Lipschitz model for Coulomb friction was consider in the unforced case. We provide sufficient conditions guaranteeing that solutions stabilizing in finite time, but observe also an infinite succession of ``stick-slip'' behavior. The last section discusses an extension to certain systems of such oscillators.
JESS at thirty: Strengths, weaknesses and future needs in the modelling of chemical speciation
International Nuclear Information System (INIS)
May, Peter M.
2015-01-01
Highlights: • Powerful chemical speciation code and database facility described. • Thermodynamic data harmonisation and automatic consistency-checking implemented. • Metal–ligand concentrations and solubilities in seawater and biofluids calculated. • Metastable equilibria included in aquatic chemistry modelling. • Limitations of ion association frameworks caused by specific-ion interactions. - Abstract: The current status of the software package JESS (Joint Expert Speciation System), which has been developed over the last 30 years, is described. Chemical speciation models of seawater and of metal-ion complexation in human blood plasma are used as large equilibrium systems to explore the present capabilities of the code and database. Strengths of JESS are considered to be (a) the power and flexibility of its command-driven programs, (b) the size, generality and openness of its reaction database, (c) its automatic facility to achieve thermodynamic consistency, and (d) its ability to partition chemical reactions to model kinetic constraints. A special feature of JESS is its ability automatically to generate a complete, stand-alone FORTRAN program for any particular chemical equilibrium model that has been developed. Weaknesses of JESS include the lack of a graphical user interface, the resulting effort required in familiarisation, and certain limitations regarding pressure and temperature corrections in concentrated solutions. However, the most troublesome issues – common to all ‘ion-association’ frameworks – are due to inadequacies in the thermodynamic data available from the literature and to persistent deficiencies in the fundamental theory of concentrated electrolyte solutions. Accordingly, work on JESS has commenced to construct a global parameterisation facility using both reaction data and the physicochemical properties of strong electrolytes in aqueous solution (including solubilities) intended to improve model function testing and to
Current problems in the weak interactions
Energy Technology Data Exchange (ETDEWEB)
Pais, A
1977-01-01
Some reasons are discussed showing why the recent SU(2) x U(1) gauge theory of weak and electromagnetic interactions is not a complete theory of these interactions, Lepton theory, charm, and the CP problem are considered. 60 references. (JFP)
Current problems in the weak interactions
International Nuclear Information System (INIS)
Pais, A.
1977-01-01
Some reasons are discussed showing why the recent SU(2) x U(1) gauge theory of weak and electromagnetic interactions is not a complete theory of these interactions, Lepton theory, charm, and the CP problem are considered. 60 references
Weakly supervised object detection with posterior regularization
Bilen, Hakan; Pedersoli, Marco; Tuytelaars, Tinne
2014-01-01
Bilen H., Pedersoli M., Tuytelaars T., ''Weakly supervised object detection with posterior regularization'', 25th British machine vision conference - BMVC 2014, 12 pp., September 1-5, 2014, Nottingham, UK.
Corruption and internal control weaknesses. Case study Romania
Directory of Open Access Journals (Sweden)
Luminiţa IONESCU
2015-03-01
Full Text Available Corruption represents one of the major causes of poverty all over the world and European Union is fighting against it. In the last few years, the corruption phenomenon registered a high level in some European countries and became one of the most problematic factors for doing business, due to the evolution of the perceived top five global risks: interstate conflict and regional consequences, extreme weather events, failure of national governance, state collapse or crises, high structural unemployment or underemployment (WEF-Global Risk Report 2015, p. 14. One of the modalities in combating corruption is implementing the internal control and most of the governments and organizations adopted strong control techniques. Most of the control weaknesses are related to the financial procedures and the number of controllers. Some of the controllers do not have enough financial expertise or do not understand the importance of informatics systems.
About some distinguishing features of weak interactions
International Nuclear Information System (INIS)
Beshtoev, Kh.M.
1999-01-01
It is shown that, in contrast to strong and electromagnetic theories, additive conserved numbers (such as lepton, aromatic and another numbers) and γ 5 anomaly do not appear in the standard weak interaction theory. It means that in this interaction the additive numbers cannot be conserved. These results are the consequence of specific character of the weak interaction: the right components of spinors do not participate in this interaction. The schemes of violation of the aromatic and lepton numbers were considered
Drift waves in a weakly ionized plasma
DEFF Research Database (Denmark)
Popovic, M.; Melchior, H.
1968-01-01
A dispersion relation for low frequency drift waves in a weakly ionized plasma has been derived, and through numerical calculations the effect of collisions between the charged and the neutral particles is estimated.......A dispersion relation for low frequency drift waves in a weakly ionized plasma has been derived, and through numerical calculations the effect of collisions between the charged and the neutral particles is estimated....
Weakly Secure Regenerating Codes for Distributed Storage
Kadhe, Swanand; Sprintson, Alex
2014-01-01
We consider the problem of secure distributed data storage under the paradigm of \\emph{weak security}, in which no \\emph{meaningful information} is leaked to the eavesdropper. More specifically, the eavesdropper cannot get any information about any individual message file or a small group of files. The key benefit of the weak security paradigm is that it incurs no loss in the storage capacity, which makes it practically appealing. In this paper, we present a coding scheme, using a coset codin...
Markovian bridges: Weak continuity and pathwise constructions
Chaumont, Loïc; Uribe Bravo, Gerónimo
2011-01-01
A Markovian bridge is a probability measure taken from a disintegration of the law of an initial part of the path of a Markov process given its terminal value. As such, Markovian bridges admit a natural parameterization in terms of the state space of the process. In the context of Feller processes with continuous transition densities, we construct by weak convergence considerations the only versions of Markovian bridges which are weakly continuous with respect to their parameter. We use this ...
Synchronization of weakly coupled canard oscillators
Köksal Ersöz, Elif; Desroches, Mathieu; Krupa, Martin
2017-01-01
International audience; Synchronization has been studied extensively in the context of weakly coupled oscillators using the so-called phase response curve (PRC) which measures how a change of the phase of an oscillator is affected by a small perturbation. This approach was based upon the work of Malkin, and it has been extended to relaxation oscillators. Namely, synchronization conditions were established under the weak coupling assumption, leading to a criterion for the existence of synchron...
Violating the Weak Cosmic Censorship Conjecture in Four-Dimensional Anti-de Sitter Space
Crisford, Toby; Santos, Jorge E.
2017-05-01
We consider time-dependent solutions of the Einstein-Maxwell equations using anti-de Sitter (AdS) boundary conditions, and provide the first counterexample to the weak cosmic censorship conjecture in four spacetime dimensions. Our counterexample is entirely formulated in the Poincaré patch of AdS. We claim that our results have important consequences for quantum gravity, most notably to the weak gravity conjecture.
Poverty + Hunger = Global Issues.
Schwartz, Richard H.
1983-01-01
Geography teachers can use mathematics to teach fourth, fifth, and sixth grade students about critical global issues. Five sample problems concerning population, poverty, waste, the arms race, and hunger are presented. The global issue related to each problem is discussed, and the solution and mathematical skill are provided. (RM)
Attending to weak signals: the leader's challenge.
Kerfoot, Karlene
2005-12-01
Halverson and Isham (2003) quote sources that report the accidental death rate of simply being in a hospital is " ... four hundred times more likely than your risk of death from traveling by train, forty times higher than driving a car, and twenty times higher than flying in a commercial aircraft" (p. 13). High-reliability organizations such as nuclear power plants and aircraft carriers have been pioneers in the business of recognizing weak signals. Weike and Sutcliffe (2001) note that high-reliability organizations distinguish themselves from others because of their mindfulness which enables them to see the significance of weak signals and to give strong interventions to weak signals. To act mindfully, these organizations have an underlying mental model of continually updating, anticipating, and focusing the possibility of failure using the intelligence that weak signals provides. Much of what happens is unexpected in health care. However, with a culture that is continually looking for weak signals, and intervenes and rescues when these signals are detected, the unexpected happens less often. This is the epitome of how leaders can build a culture of safety that focuses on recognizing the weak signals to manage the unforeseen.
Cairns, John
2010-01-01
Humankind is facing six interactive global crises: (1) climate change, (2) overpopulation, (3) species impoverishment (i.e., loss of biodiversity), (4) ecological overshoot (i.e., ecological deficit), (5) excessive use of fossil fuels (i.e., which release carbon dioxide when burned), (6) inadequate food and water. Since, the crises are interactive, they must be resolved simultaneously; furthermore, since they are all global, only a global solution by all nations will suffice. Since these cris...
Said-Houari, Belkacem
2012-09-01
The goal of this work is to study a model of the viscoelastic wave equation with nonlinear boundary/interior sources and a nonlinear interior damping. First, applying the Faedo-Galerkin approximations combined with the compactness method to obtain existence of regular global solutions to an auxiliary problem with globally Lipschitz source terms and with initial data in the potential well. It is important to emphasize that it is not possible to consider density arguments to pass from regular to weak solutions if one considers regular solutions of our problem where the source terms are locally Lipschitz functions. To overcome this difficulty, we use an approximation method involving truncated sources and adapting the ideas in [13] to show that the existence of weak solutions can still be obtained for our problem. Second, we show that under some restrictions on the initial data and if the interior source dominates the interior damping term, then the solution ceases to exist and blows up in finite time provided that the initial data are large enough.
Importance of weak minerals on earthquake mechanics
Kaneki, S.; Hirono, T.
2017-12-01
The role of weak minerals such as smectite and talc on earthquake mechanics is one of the important issues, and has been debated for recent several decades. Traditionally weak minerals in fault have been reported to weaken fault strength causing from its low frictional resistance. Furthermore, velocity-strengthening behavior of such weak mineral (talc) is considered to responsible for fault creep (aseismic slip) in the San Andreas fault. In contrast, recent studies reported that large amount of weak smectite in the Japan Trench could facilitate gigantic seismic slip during the 2011 Tohoku-oki earthquake. To investigate the role of weak minerals on rupture propagation process and magnitude of slip, we focus on the frictional properties of carbonaceous materials (CMs), which is the representative weak materials widely distributed in and around the convergent boundaries. Field observation and geochemical analyses revealed that graphitized CMs-layer is distributed along the slip surface of a fossil plate-subduction fault. Laboratory friction experiments demonstrated that pure quartz, bulk mixtures with bituminous coal (1 wt.%), and quartz with layered coal samples exhibited almost similar frictional properties (initial, yield, and dynamic friction). However, mixtures of quartz (99 wt.%) and layered graphite (1 wt.%) showed significantly lower initial and yield friction coefficient (0.31 and 0.50, respectively). Furthermore, the stress ratio S, defined as (yield stress-initial stress)/(initial stress-dynamic stress), increased in layered graphite samples (1.97) compared to quartz samples (0.14). Similar trend was observed in smectite-rich fault gouge. By referring the reported results of dynamic rupture propagation simulation using S ratio of 1.4 (typical value for the Japan Trench) and 2.0 (this study), we confirmed that higher S ratio results in smaller slip distance by approximately 20 %. On the basis of these results, we could conclude that weak minerals have lower
SIMULATION OF SUBGRADE EMBANKMENT ON WEAK BASE
Directory of Open Access Journals (Sweden)
V. D. Petrenko
2015-08-01
Full Text Available Purpose. This article provides: the question of the sustainability of the subgrade on a weak base is considered in the paper. It is proposed to use the method of jet grouting. Investigation of the possibility of a weak base has an effect on the overall deformation of the subgrade; the identification and optimization of the parameters of subgrade based on studies using numerical simulation. Methodology. The theoretical studies of the stress-strain state of the base and subgrade embankment by modeling in the software package LIRA have been conducted to achieve this goal. Findings. After making the necessary calculations perform building fields of a subsidence, borders cramped thickness, bed’s coefficients of Pasternak and Winkler. The diagrams construction of vertical stress performs at any point of load application. Also, using the software system may perform peer review subsidence, rolls railroad tracks in natural and consolidated basis. Originality. For weak soils is the most appropriate nonlinear model of the base with the existing areas of both elastic and limit equilibrium, mixed problem of the theory of elasticity and plasticity. Practical value. By increasing the load on the weak base as a result of the second track construction, adds embankment or increasing axial load when changing the rolling stock process of sedimentation and consolidation may continue again. Therefore, one of the feasible and promising options for the design and reconstruction of embankments on weak bases is to strengthen the bases with the help of jet grouting. With the expansion of the railway infrastructure, increasing speed and weight of the rolling stock is necessary to ensure the stability of the subgrade on weak bases. LIRA software package allows you to perform all the necessary calculations for the selection of a proper way of strengthening weak bases.
The Problem of Weak Governments and Weak Societies in Eastern Europe
Directory of Open Access Journals (Sweden)
Marko Grdešić
2008-01-01
Full Text Available This paper argues that, for Eastern Europe, the simultaneous presence of weak governments and weak societies is a crucial obstacle which must be faced by analysts and reformers. The understanding of other normatively significant processes will be deficient without a consciousness-raising deliberation on this problem and its implications. This paper seeks to articulate the “relational” approach to state and society. In addition, the paper lays out a typology of possible patterns of relationship between state and society, dependent on whether the state is weak or strong and whether society is weak or strong. Comparative data are presented in order to provide an empirical support for the theses. Finally, the paper outlines two reform approaches which could enable breaking the vicious circle emerging in the context of weak governments and weak societies.
Controlling the swelling and wettability of weak polyelectrolyte brushes
Gurtowski, Richard; Jing, Benxin; Zhu, Elaine
2011-03-01
Weak polyelectrolytes (PE) of tunable ionization shows great potential as ``smart'' polymer materials for diverse applications from drug delivery to energy storage. However, the conformational dynamics of surfaced-tethered weak PE chains remain inadequately understood due to the complexity of their dynamic charge states in response to solvation and surface immobilization conditions. In this work, we investigate the wetting and swelling characteristics of poly(2-vinyl pyridine) (P2VP) brushes grafted to a gold substrate by AFM and water contact angle measurements. We observe the collapse of P2VP brushes, accompanied with increased surface hydrophobicity, as increasing solution pH across a critical transition pH, which is considerably lower than the pKa of free P2VP chains in bulk solution. Surprisingly, the broadness of the transition pH range shows a strong dependence with brush thickness, but not grafting density, suggesting a distribution of chain ionization along grafted P2VP brushes. We further manipulate P2VP brush structures by applying ac-electric fields across the brushes to make tunable and switchable polymer surfaces.
Global Existence Analysis of Cross-Diffusion Population Systems for Multiple Species
Chen, Xiuqing; Daus, Esther S.; Jüngel, Ansgar
2018-02-01
The existence of global-in-time weak solutions to reaction-cross-diffusion systems for an arbitrary number of competing population species is proved. The equations can be derived from an on-lattice random-walk model with general transition rates. In the case of linear transition rates, it extends the two-species population model of Shigesada, Kawasaki, and Teramoto. The equations are considered in a bounded domain with homogeneous Neumann boundary conditions. The existence proof is based on a refined entropy method and a new approximation scheme. Global existence follows under a detailed balance or weak cross-diffusion condition. The detailed balance condition is related to the symmetry of the mobility matrix, which mirrors Onsager's principle in thermodynamics. Under detailed balance (and without reaction) the entropy is nonincreasing in time, but counter-examples show that the entropy may increase initially if detailed balance does not hold.
Geometric phase topology in weak measurement
Samlan, C. T.; Viswanathan, Nirmal K.
2017-12-01
The geometric phase visualization proposed by Bhandari (R Bhandari 1997 Phys. Rep. 281 1–64) in the ellipticity-ellipse orientation basis of the polarization ellipse of light is implemented to understand the geometric aspects of weak measurement. The weak interaction of a pre-selected state, acheived via spin-Hall effect of light (SHEL), results in a spread in the polarization ellipticity (η) or ellipse orientation (χ) depending on the resulting spatial or angular shift, respectively. The post-selection leads to the projection of the η spread in the complementary χ basis results in the appearance of a geometric phase with helical phase topology in the η ‑ χ parameter space. By representing the weak measurement on the Poincaré sphere and using Jones calculus, the complex weak value and the geometric phase topology are obtained. This deeper understanding of the weak measurement process enabled us to explore the techniques’ capabilities maximally, as demonstrated via SHEL in two examples—external reflection at glass-air interface and transmission through a tilted half-wave plate.